It is certainly true that anyone who visits the wilder parts of Ceylon [Sri Lanka] is liable to be set upon by leeches, but not many people would think of sitting down at a table to play a game with them. Baker noticed that the leech is not only chemically attracted to the human body but it is also strongly phototropic. Thus a leech placed upon a table illuminated by a table lamp can be controlled in the direction of its movements by periodically changing the position of one’s seat or of the table lamp.
The abundance of land-leeches (Haemadipsa zeylanica, Moquin-Tandon) greatly detracts from the pleasure of studying the Sinharaja Forest. I found it best to wear thin breeches cut like "plus-fours," stockings, boots with the tongues sewn in right up to the top, and puttees. This clothing by no means prevents leeches from penetrating to the skin of one's legs, but it greatly reduces the annoyance.
Here is Baker’s map of Sinharaja:
And here is a very short video of the leech in question and its acquisition of my blood:
John Randal Baker (1900-1984) was, and still is, well known for a number of different activities: the breeding season of birds in the tropics and the factors that trigger the onset of reproduction; the introduction of the terms proximate and ultimate causation; his cytological studies and textbook on the subject; his work on chemical contraception; his wars, especially with J. Brontë Gatenby, on the existence of the Golgi apparatus.