John Samuel Budgett died, aged 31, on 19 January 1904 of blackwater fever and malaria. He became famous because of his four expeditions to Africa in search of eggs and developing young of the strange fish, Polypterus. There had been all sorts of theories about Polypterus: that it was the ‘missing link’ between fish and amphibia; that it might even been an amphibian. Thomas Henry Huxley had considered it closely related to the the lungfish and the coelacanths, other fish with lobed fins. Eventually Budgett succeeded but did not live to present or publish the results. On the day of his death he was due to give paper to the Zoological Society of London. Polypterus is an ‘early’ finned fish, nowhere near any possible line of descent from fish to amphibian.
Budgett was following the Cambridge tradition established in the 1870s and 80s of using embryology as a tool to unravel evolutionary relationships. An exponent of the Cambridge embryological approach was John Graham Kerr. As a new graduate seeking to work on the lungfish, Lepidosiren, Kerr took Budgett on a collecting expedition in 1896/97 to the Paraguayan Chaco in order to collect material. During their trip Budgett also collected amphibians and reptiles. He found two new species, one of which. Lepidobatrachus laevis, is known as Budgett’s frog.
Budgett collected eggs and tadpoles in Paraguay as well as in Africa during his searches for Polypterus. Before his death he had worked on the development of one species collected in the Chaco. However, he left a great deal of material in Cambridge. At the time of Budgett’s death Kerr had moved from Cambridge to Glasgow, taking Edward Bles with him. Bles started to work on the eggs and tadpoles collected by Budgett both in South America and in Africa. Bles’s words take up the story:
When this material was handed over to me I was much impressed by its interesting character and still further impressed by the novelty of the Engystomid [narrow-mouthed] embryos of Hemisus and, as the series of stages of the last two forms were not extensive, I determined to make an effort to obtain more material and obtained six months leave for a voyage to S. America. I spent almost the whole of the time available—May to August 1905—at San Bernardino on Lake Ipacaraÿ in Paraguay. Unfortunately the winter was most exceptionally cold and there were great floods over immense tracts in Brazil, Paraguay, and the Argentine Republic. Lake Ipacaraÿ had also flooded its shores and my main objects, to collect vertebrate embryological material, were completely defeated. The frogs did not breed during that winter in Paraguay, the only tadpoles found were late hibernating stages.
The area he chose was where Kerr and Budgett had collected nearly ten years earlier. The eggs and tadpoles Bles was hoping to collect is now known as Physalaemus biligonigerus, the Four-eyed Weeping Frog. To get to Paraguay he sailed with his wife from Liverpool on 30 March 1905 on the S.S. Oravia heading for Buenos Aires. After what must been an extremely disappointing few months they arrived back in U.K. on 5 August, disembarking at Southampton from the S.S. Danube. Bles had suffered the well-known syndrome of ‘you should have been here last week/month/year; we were falling over them’.
 |
| Physalaemus biligonigerus (Raúl Maneyro) http://calphotos. berkeley.edu |
The African species Budgett collected was Hemisus marmoratus, the Marbled Snout-burrower or Pig-nosed Frog or even Shovel-nosed Frog. Bles wrote up the description of the development of both species for a chapter in a memorial volume in honour of Budgett and his achievements compiled and edited by Kerr. Kerr himself completed the Polypterus story. Cambridge University Press published the book in 1907; it was reprinted in 2014.
 |
| Hemisus marmoratus (Ryanvanhuysteen) |
 |
| John Samuel Budgett |
Bles EJ. 1907. Notes on anuran development: Paludicola, Hemisus and Phyllomedusa. In The Work of John Samuel Budgett, Balfour Student of the University of Cambridge. Edited by J. Graham Kerr, pp 443-458 plus 6 plates. Cambridge University Press.
No comments:
Post a Comment