Tuesday, 15 August 2017

1957-2017: The Diamond Jubilee of Salt Glands: Knut Schmidt-Nielsen's Major Discovery

As i wrote in this post on Bill Sladen, this year, 2017, marks the 60th anniversary of the announcement of the discovery of salt glands by Knut Schmidt-Nielsen and the publication of an abstract describing the work in Federation Proceedings. The talk was given to the American Physiological Society at the Federation of American Societies for Experimental Biology meeting in Spring 1957. A search shows this meeting was held in Chicago on 15-19 April. I also found from the bibliography published alongside his obituary as a Foreign Member of the Royal Society that he had also given a paper in 1957 to the Elisha Mitchell Scientific Society in North Carolina and an abstract was published* (which I have not seen); he was by then based at Duke University in North Carolina.

Salt glands are still fascinating: they turn on within minutes of excess salt being detected in the blood; although small in size they can secrete concentrated salt solutions at a very high rate, and to support this blood flow through them is amongst the highest recorded in the animal kingdom. Even now there remains much to be known about them, from the ecological level, the extent to which the salt glands are used by different birds in different habitats, for example, right down to secretory mechanism at the cellular and molecular levels.

The story of the discovery of salt glands is in Knut’s autobiography, The Camel’s Nose, published in 1998. His curiosity was aroused when asked to read the proofs of Nobel prize-winning (and soon to be his father-in-law) August Krogh’s book on osmotic regulation. The story actually begins  in 1939. He wrote:

     I learned a great deal from reading the proofs for Krogh's osmoregulation book. One problem that especially intrigued me was how marine birds survive with no fresh water to drink. In search of an answer to this question, I developed methods I could use under primitive conditions, and at the end of the spring term in 1939, after securing permission from the Norwegian authorities to capture birds, I set off for the coast of northern Norway to try to solve the problem. This journey was the first of what would become a long series of field studies around the world, ranging from the Sahara Desert to the Amazon River, seeking answers to problems of how animals survive in hostile environments. 
     In mid-June 1939 I arrived at Röst, a small island in northern Norway, off the Lofoten chain and facing the Arctic Ocean. Millions of auks, puffins, and gulls nest on vertical cliffs that rise out of the ocean beyond Röst. The birds seek their food at sea, and except for rainfall there is no fresh water. Do they drink sea water? I wanted to find out. 
     It was already known how whales and seals can manage. If they drink sea water, the extra salt is excreted by the kidneys. Whale kidneys are powerful and can produce urine more concentrated than sea water. Although no one knows whether whales and seals actually drink sea water, they could readily eliminate the excess salt… 
     Humans have less powerful kidneys than seals and whales. A human castaway at sea who drinks sea water merely hastens the approach of death because the kidneys are unable to excrete the excess salts. Birds seemingly are worse off; their kidneys are even less efficient than humans' in eliminating salts. The problem was to find out if birds get sufficient water in their food, or if they drink sea water and somehow are able to excrete the salts… 
     During the summer I examined skuas, auks, puffins, and kittiwake gulls. The salt concentration in their guts was invariably low and showed no evidence that any of them drank sea water. I also examined five seals shot by a local fisherman; the results were similar. Neither the salt nor magnesium content in the seals' stomachs and intestines suggested that they had drunk sea water. 
     So far I had only negative evidence. The next step was to find out what happens when a bird actually swallows sea water. I captured a few kittiwake gulls and caged them in empty orange crates. They greedily devoured the fish I fed them. Fish doesn't have a high salt content, so I gave one of the birds an ample volume of sea water by stomach tube. If the kidneys excreted the salts, there should be a high salt concentration in the urine. 
     The bird produced copious volumes of urine, but to my amazement the urine had little salt in it. I repeated the experiment with other birds, and again the urine was nearly salt-free. Wondering if my analytical methods were wrong, I tested every step with solutions of known salt content; my methods were 100 percent correct. 
     No matter how much sea water I gave the birds, little salt appeared in the urine. Could it be that the birds retained the salts? If so, the salt concentration in the blood should increase. But my analysis of their blood showed no elevated salt levels. Where was the salt going? I knew it had entered the body, yet I couldn't find it in the urine or in the blood. It seemed that the salt had simply disappeared. 
     At the end of the summer I returned to Copenhagen, disappointed that I had found no solution to the original problem. I was anxious to talk to Dr. P. B. Rehberg, a prominent renal physiologist, who usually gave young scientists excellent advice. However, he said little, and I felt that he perhaps thought I hadn't done a very good job; he didn't even look at my meticulously kept data books. In desperation I suggested that if the salt doesn't come out the rear of the bird, it must somehow come out the front. Rehberg didn't comment… 
     I wanted to tackle this problem again, but the war intervened, and then other projects took all my time. Not until eighteen years later, in 1957 [actually 1956], did I return to the study of marine birds. As I had suggested to Rehberg, a salt load is indeed eliminated from the front end of the bird, as a salty fluid dripping from its beak. Then I understood why I hadn't noticed the phenomenon when I was on Röst. The primitive conditions where I worked, the orange crates and the rough wooden floor, made it difficult to see drops of fluid the birds shook from their beaks. That summer in Norway, I thought the few drops I noticed were no more than a little sea water regurgitated by the bird.
    
The research that led to the discovery of salt glands was done during the summer of 1956 at Mount Desert Island Biological Laboratory (MDIBL), Bar Harbor, Maine, then a gathering place for those studying the kidney and renal excretion during the long vacation, including Knut’s then wife, Bodil, August Krogh’s daughter.

Knut took up the story again in The Camel’s Nose:

     For the study of marine birds I asked two postdoctoral collaborators to join me in Maine: Humio Osaki from Japan and a former classmate of mine from Denmark, Carl Barker Jörgensen. We caught some young cormorants, and to find out what effect sea water has on salt excretion, I gave one of them a liberal amount by stomach tube and placed the bird in a carefully cleaned plastic container. Within a minute or two I made the fastest scientific discovery I ever made. I noticed that the bird, with a quick movement of the head, shook off droplets of fluid that appeared at the tip of its beak. I sampled the clear liquid with a micropipette; it gave a massive precipitate with silver nitrate, revealing a high concentration of chloride. We were astounded, but the result confirmed what I had suggested decades before—that if salts do not come out one end of the bird, they must come out the other. 
     The very salty secretion is produced by glands in the bird's head and drips from the tip of the beak. Thus, if the birds drink sea water, the excess salt is eliminated, leaving a net gain of free water. Whether marine birds in the wild actually drink sea water is a question that is difficult to answer. Nevertheless, much of their food has a salt content high enough to necessitate the elimination of excess salt by the glands we had discovered. For simplicity we decided to call them salt glands. Our discovery received a great deal of attention from physiologists as well as the popular press, for no such gland was known in any animal, and it solved a long-standing problem. 
     I continued these studies over the next two years, both at Duke and in Maine. All marine birds we examined—gulls, pelicans, petrels, eider ducks, and so on—use the same mechanism to excrete excess salt. I had a marvelous collaborator in a Swedish friend, the animal physiologist Ragnar Fänge, who described the detailed anatomy of the salt gland and refined our understanding of its function.


Knut Schmidt-Nielsen working on sea birds at MDIBL
(from here)


Schmidt-Nielsen spent the following summers until 1959 at MDIBL, adding to the previous work. The history also showed that he worked with the MDIBL stalwarts, William L Doyle and Thomas H Maren but they published their salt-gland work without Knut as a co-author. Doyle published the first electron micrographs of the gland. Others there also published on salt glands later, Hubert and Mabel Frings, for example. 

The discovery of salt glands in birds and then in reptiles was just one part of Knut Schmidt-Nielsen’s series of seminal contributions to How Animals Work (the title of one of his books). Obituaries by the late Steven Vogel (1940-2015) and Ewald Weibel can be found here and here.

As Steven Vogel (1940-2015) wrote in Knut’s obituary, in discussing the discovery of salt glands, ‘…the work has taken its place as common knowledge with only rare reference to the seminal reports’. I can only add that, sadly, not only are the references to the seminal reports rare but that the information given on salt glands, particularly in blogs and websites, is so often completely, utterly and completely wrong that it can only be classified as drivel.

At a symposium in Sandbjerg, Denmark to celebrate Knut Schmidt-Nielsen’s 65th birthday in July 1980 there were seven co-authors (out of a possible ten) of his papers on salt glands that were all published between 1957 and 1964 (Ragnar Fänge (1920-1999), Carl Barker Jörgensen (1915-2007) , Maryanne Robinson (Maryanne Robinson Hughes), Arieh Borut, Eugene C. Crawford, Stephen Thesleff, Francis G Carey (1931-1994)). In addition, two of us there (Dennis Bellamy and me) had worked on salt glands later. All the participants and contributors to the proceedings, entitled A Companion to Animal Physiology, received a commemorative medal which show Schmidt-Nielsen’s famous books and the animals with which he was most associated: kangaroo rats, gulls, camels, frogs and snails.


5th International Symposium on Comparative Physiology, Sandbjerg, Denmark, July 1980
To commemorate Knut Schmidt-Nielsen's 65th birthday




And there were Golden Orioles in the trees.


Taylor CR, Johansen K, Bolis L (editors). 1982. A Companion to Animal Physiology: Perspectives. Cambridge: Cambridge University Press

Evans DH. 2015. Marine Physiology Down East: The Story of My Desert Island Biological Laboratory. New York: Springer

*Schmidt-Nielsen K. 1957. Extrarenal excretion of salt in birds. J Elisha Mitchell Scientific Society 73, 235

Saturday, 12 August 2017

The Kitching-Ebling split, Lough Ine (Hyne) and Reflections on a Summer Sea

Scientific divorces, whether of long-term collaborators, scientist and technician or scientist and past research student,  are horrendous—both to both the parties involved and to onlookers and friends. The reasons are often obscure and may take years to come to the boil. Jealousy, perceived slights, perceptions of unequal work load can all come into the mix.

One of the saddest cases was that of Jack Kitching* and John Ebling†. Their exploits each summer in exploring the ecology of Lough Ine, or Hyne as it is now known, a sea-loch in Ireland, with zoology students initially from Bristol and then, when Kitching moved, from the University of East Anglia, was known more widely and it was a constant feature in both of their lives from 1937 and 1938. Kitching was then a young lecturer and Ebling an undergraduate. They published many papers together and pioneered an experimental approach to ecology. Ebling moved from Bristol, had a short spell in Hull and then established himself in Sheffield where he rose through the ranks to the second professorship in zoology—then a vary rare promotion. Throughout, he headed the logistics of getting the equipment and people to Ireland each year and organising the supplies of food and alcohol. There seems no doubt, though, that Kitching regarded Loch Ine as his show and as his territory.


The Kitching and Ebling Summer Show at Loch Ine was captured superbly by Trevor Norton’s 2001 book, Reflections on a Summer Sea. He began it by quoting a letter he had written to Jack Kitching in 1994:

I have begun to write the story of Lough Ine. I want to tell of the stunning scenery and terrible history of the place, the myth and the magic, and to recapture all the fun and excitement we had in those summers when we waded and dived in the lough. Perhaps I can convey the wonder I felt when I first came to Lough Ine in the 1960s, and maybe slip in a bit of marine biology too…

and continued:

This is the story of the menagerie of eccentric and talented ecologists who, as a hobby, established a privately owned field laboratory in south-west Ireland and took part in one of the most unlikely projects in the history of marine biology.

I heard of the Kitching-Ebling split around 1987 from John Ebling himself. I found him or, more correctly, heard him, holding forth in the Staff Club at Sheffield in, I think 1987 or ’88. I left my host and went over to talk to him. In our student years in the 1960s, John had waxed lyrical about the summers on Lough Ine and so I asked him if he was still going. ‘No’, was the reply and he went on to explain that Kitching had cut all ties with him some years earlier and that he was no longer welcome. He was clearly distressed and utterly bewildered about the whole affair. We moved on to pleasanter matters and I left him to resume his conversation. That was the last time I saw him.

Trevor Norton saw at close hand the whole relationship between Kitching and Ebling and the eventual break up. The immediate cause appeared to be Kitching’s proprietorial attitude to Lough Ine and his attempting to hang on in research after his retirement against a background of tightening funding and lack of recognition of the importance of work there. It would also seem that Kitching came to resent his former student’s success in other fields, for John was at home with errant polychaetes, moulting patterns of mammals, hormonal effects on the skin, clinical dermatology and the effects of cosmetics.

So while it seems pretty clear that John Ebling was the injured party, as was Trevor Norton himself when he disagreed with Kitching on the direction the research should take, there did come a sort of and rather sad rapprochement. Trevor described a symposium in Cork in 1990 on the research at Lough Ine. Kitching and Ebling were both invited:

Although it was a relief to John to have an invitation and a chance to visit the lough, he was nervous about meeting Jack again. He needn’t have been, for Jack was no longer formidable. John was a ebullient as ever, but a stroke had stolen Jack’s vigour. He looked and sounded frail, a ghost of his old self. I feared his lecture might be a disaster, but on stage he rose to the occasion and spoke well. I saw John helping him across the road. They were chatting, perhaps about old times.

There Trevor left it and so I was delighted to find that a book of photographs illustrating the history of the people who made Lough Ine famous—now the subject of over 450 scientific publications had been published in 2011. Many of the photographs are Trevor Norton’s but it covers work from 1885, when the first studies of the lough were made, until 2010. When I received my copy I was delighted to recognise people I had met and worked alongside in parallel universes without knowing they had spent one or more summers there.

I cannot help but end with a John Ebling story. Trevor Norton explains how Jack Kitching disapproved of John’s ribald sense of humour especially in front of the students, “these tender plants”. My abiding memory is of Venice at Easter 1964. We had arrived by bus from Rovinj where we were being exposed to a marine biology field trip (Lough Ine lite is the best description I can think of with hindsight). The bus journey had taken several hours and we were dropped off at a vaporetto-stop where we found public lavatories before heading for St Mark’s Square. Italy at that time had the lira and inflation had led to massive numbers of lira being needed for everything. The relatively small number of men and the larger number of women lined up with John heading the queue (student prostates were smaller and bladders possibly bigger) to pay and enter. After several minutes inside he re-appeared. ‘I am reminded of that old rhyme written behind the door in gents’ lavatories’, he said. And continued:

Here I sit, broken hearted, 
Paid two-thousand lira and only farted.

I cannot enter a public lavatory anywhere in Europe without repeating that incantation. Kitching would not have been amused.

These are photographs from Terri Kearney's superb book of photographs:


Jack Kitching on his first visit in 1938
Ebling and Kitching on the front row at the conference in Cork when they met again in 1990

*John (“Jack”) Alwyne Kitching OBE FRS (1908-1996)
†Francis John Govier Ebling (1918-1992)

Norton T. 2001. Reflections on a Summer Sea. Century (paperback 2002, Arrow Books)

Kearney T. 2011. Lough Hyne. The Marine Researchers - in Pictures. Skibereen Heritage Centre. Obtainable from here.

Sunday, 6 August 2017

Bill Sladen (1920-2017): Penguins and Salt Glands

A number obituaries of William Joseph Lambart Sladen who died on 29 May aged 96 have been published in recent weeks. While they all record his pioneering studies on penguins in the Antarctic, his later involvement with migration and conservation projects in the northern hemisphere and his detection of DDT in penguins in the 1960s, they do not mention his involvement with a major scientific discovery of the 1950s which explained how penguins and other birds survive at sea.


Obituary in The Times

This year, marks the 60th anniversary of the announcement of the discovery of salt glands by Knut Schmidt-Nielsen and the publication of an abstract describing the work in Federation Proceedings. A full paper appeared in the American Journal of Physiology in March 1958. A month later a paper in Nature appeared entitled, Nasal salt secretion in the Humboldt Penguin by Schmidt-Nielsen and Sladen, which suggests that the work was done only a short time after that reported in the first paper on the Double-crested Cormorant Phalacrocorax auritus.

Schmidt-Nielsen and Sladen wrote:


In order to establish whether extra-renal salt excretion is of importance in the salt balance of other marine birds, we took advantage of the colony of Humboldt’s penguins (Spheniscus humboldti) in the laboratory of one of us (W.S.). These birds had been caught in the wild six months before, they were doing well in captivity, and were considered to be free of disease. Trial experiments in April 1957 showed that nasal secretion did occur, so the following experiments were performed.

The rest, as they say, is history.

How Schmidt-Nielsen and Sladen got together to do the study I do not know. Since the penguins were kept in Sladen’s lab at Johns Hopkins, I assume the male penguin used was given its salt-loaded fish in Baltimore.


I found this photograph of an Emperor Penguin skull which shows the
supra-orbital position of the nasal salt glands

Sladen by this time had already made his name from studying penguins in the Antarctic. British-born, medically-qualified and working as medical officer as well as biologist for the Falkland Islands Dependency Survey—FIDS—now the British Antarctic Survey, he was sole witness to the horrendous hut fire at Hope Bay in November 1948 that resulted in the death of two members of the survey team. After the fire he spent the next sixteen days alone and out of radio contact, sleeping in a tent, until the main survey party returned. He continued his work on penguins during this time, writing his Oxford doctoral thesis in Charles Elton’s Bureau of Animal Population.

Sladen moved to the U.S.A. in 1956, initially on a research fellowship, and became a U.S. citizen in 1962. He remained based at Johns Hopkins while commuting to the Antarctic and Arctic for his research.


Adélie Penguin - adult and chick
Sladen's early work was on this species at Hope Bay, 9 miles along the
coast from Brown Bluff on the Antarctic Peninsula where I took these
photographs on 26 January 2005.

Salt-gland secretion in this species was described by Donald S Douglas
in the 1960s.

I am taking video of the tens of thousands of Adélie
Penguins at Brown Bluff

Schmidt-Nielsen K, Jörgensen CB, Osaki H. 1957. Secretion of hypertonic solutions in salt glands. Federation Proceedings 16, 113-114

Schmidt-Nielsen K, Jörgensen CB, Osaki H. 1958. Extrarenal salt excretion in birds. American Journal of Physiology 193, 101-107

Schmidt-Nielsen K, Sladen WJL. 1958. Nasal salt secretion in the Humboldt penguin. Nature 181, 1217-1218

Saturday, 5 August 2017

Charles Eliot: languages, embassies, universities and nudibranch molluscs

It is difficult to believe that Sir Charles Eliot (1862-1931) who achieved great distinction in languages, culture and comparative religion and who served as a British diplomat and as vice-chancellor of two new universities developed as a hobby the study of nudibranch molluscs and published a number of authoritative papers on their taxonomy and phylogeny.





Knowledge stuck to him ‘like fly-paper’ and he came to have twenty-seven languages at his command, often acquired at amazing speed. He published a first grammar in English of Finnish. From Oxford, he joined the diplomatic service and served in Russia, Morocco, Turkey and the USA. He also served as British Commissioner in Samoa.

While Commissioner, Commander-in-Chief and Consul-General for the East Africa Protectorate Eliot had a strong disagreement with the Foreign Secretary over who should be allowed to buy land. He resigned by means of an open telegram. After that dramatic resignation from the diplomatic service he was appointed Vice-Chancellor of the new University of Sheffield in 1905. In effect he was the first vice-chancellor but W.M. Hicks who was Principal of the university college that was to be a constituent of the new university did not want to become vice-chancellor but to continue as Professor of Physics. Hicks, because he had done all the work to establish the university, was persuaded to be named as Vice-Chancellor in the Charter but then to hand over to Eliot immediately afterwards. It is clear that to many observers, Eliot was not the ideal Vice-Chancellor. Shy and withdrawn other than with personal friends—and ‘given to formidable silences’—he left the administrative work to the Registrar and throughout each vacation travelled widely in the East. However, it is clear that his hands-off approach worked because the new university thrived.

In 1912, he took on another new university—this time Hong Hong and it had hardly reached the embryonic stage by the time of his arrival. There were only three full-time members of staff. Eliot’s diplomatic skills soon brought in money from the wealthy Chinese in Hong Kong and Malaya. He was noted as being completely ignorant of finances and had an aversion to mechanical devices; he refused to use the telephone. In Hong Kong, he had daily lessons in Mandarin. Again, such was his devotion to acquiring a language, he later translated into English three large volumes of Chinese Buddhist scriptures. Although he had no need to do so, he lectured and held tutorials such that he was popular with the students. A student hall of residence was named to commemorate his vice-chancellorship in 1914. The Hall lost its name after the landslide in 1966 when the three halls, built one above the other were combined into one. However, more recently it was retained when one of the halls was demolished and is now back as Eliot Hall.

He was recalled by the Foreign Office to the temporary job of High Commissioner in Siberia in 1918. He did not return to Hong Kong because he was appointed British Ambassador in Tokyo.

Throughout his life Eliot was a prolific writer on his observations during travel and on eastern religions. After his retirement from the embassy in Tokyo, he remained in Japan for five years. Suffering from heart disease he was returning to Britain by sea when his condition deteriorated. Advised to stay ashore when the ship reached Singapore from Kobe, he opted to continue. on 17 March 1931 he died on board the Japanese ship Hakone Maru approximately midway between Penang and Colombo. The captain of the ship conducted a burial at sea with, since there was no one on board to do otherwise, Buddhist rites. The ceremony was described in The Times of 7 April. Appropriately, it would seem, Eliot’s book Japanese Buddhism was published posthumously, in 1935.


Embed from Getty Images


The story of Eliot’s interest in nudibranchs is that while in Samoa in 1899 he became fascinated by their beauty and behaviour. He quickly acquired sufficient knowledge to publish a paper on the Samoan nudibranchs. After that he worked on the local nudibranch fauna wherever he was posted as a diplomat and on collections from a number of expeditions, including the Scottish National Antarctic Expedition of 1902-1904. What does not seem to have been picked up by his biographers is that Eliot appointed a key member of that expedition—Robert Rudmose Brown (1879-1957)—as lecturer in geography in Sheffield. In Sheffield, Eliot had his own laboratory to which he retired when not busy as vice-chancellor. I have already explained how Eliot resigned from the diplomatic service on a point of principle, He was no ‘yes’ man and his comment in a letter to another vice-chancellor shows his disgust for an early manifestation of the imposition of pseudo-accountability. He complained that the Board of Education:


…want to know how many hours the Professors lecture. Nothing so ungentlemanly has been done by the Government since they actually insisted on knowing at what time Foreign Office clerks arrive in Whitehall.

I have Eliot down as one of the good guys.




From Eliot's paper, On some nudibranchs from east Africa and Zanzibar.
Part VI. Proceedings of the Zoological Society of London
1905 2, 268-298, plates 16-17


Blunden E. 1962. Sir Charles Eliot. In, University of Hong Kong. The First 50 Years, 1911-1961. edited by Brian Harrison. Hong Kong University Press.

Chapman AW. 1955. The Story of a Modern University. A History of the University of Sheffield. Oxford University Press

Mellor B. 1980. The University of Hong Kong. An Informal History. Volume 1. Hong Kong University Press

R.W. Obituary: Sir Charles Eliot, 1862–1931. Journal of Molluscan Studies 19, Issue 5, 224–226

A list of Eliot’s papers on nudibranchs can be found here.