ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 245 



Quekett Microscopical Club. — The 461st Ordinary Meeting of the 

 Club was held on December 28, 1909, the President, Professor E. A. 

 Minchin, M.A. F.Z.S., in the Chair. Mr. R. T. Lewis, F.R.M.S., gave 

 an interesting account of " The Pollination of the Asclepiads." His 

 attention had been drawn to the subject by the rinding of dried pollen- 

 sacs of one of this genus firmly attached to the feet of some insect speci- 

 mens received from Lindley, O.R.C. A reference to Kerner and Oliver's 

 " Vegetable Kingdom, ii. pp. 257-9, was given. 



The 462nd Ordinary Meeting was held on January 25, 1910, the 

 President in the Chair. Mr. James Murray, one of the scientific staff on 

 board the ' Nimrod,' gave an interesting account of the aquatic organisms 

 taken in the Antarctic by Lieut. Shackleton's expedition. Preparations 

 by Mr. Rousselet from material brought home by the expedition were 

 shown of PMJodina gregaria, which occurred in great abundance ; P. 

 alata, remarkable for its large lateral processes ; Adineta grandis sp. n., 

 from Ross Island ; and Hgdalina senta. 



At the 44th Annual General Meeting, held on February 22, the Presi- 

 dent, Professor E. A. Minchin, M.A. F.Z.S., delivered the annual address, 

 taking for his subject, " Some Considerations on the Phenomena of 

 Parasitism amongst Protozoa." In the sense under discussion a Protozoan 

 is a parasite when it lives at the expense of another animal, called its 

 " host." Such parasites may live on the host (epizoic) or in it (entozoic). 

 Both these classes may be further divided into non-lethal (harmless) and 

 lethal, or disease-producing, species. The lethal powers of the latter class 

 are most probably due to specific toxic effects produced by them. Lethal 

 species may be regarded as exceptional and aberrant forms, the majority 

 of Protozoan parasites being harmless. After dealing briefly with the 

 few known cases of active migration of parasites to infect a new host, 

 the special methods of dissemination, of which at least six are known, 

 where the escape of the parasite by anatomical channels is not possible, 

 were described at some length. Sir E. Ray Lankester had suggested that 

 the extinction of animals seen in past geological periods may have been 

 due, in some cases, to their extirpation by some species of parasite new 

 to them, and consequently very deadly. In proposing a vote of thanks 

 to the President, the Chairman, Mr. C. F. Rousselet, F.R.M.S., said that 

 when recently in Canada he had heard it suggested that the extinction of 

 the vast herds of buffalo was caused by some peculiar parasitic malady. 



B. Technique.* 

 (1) Collecting: Objects, including- Culture Processes. 



Cultivation of Leishmania Donovani in Fluid Media, f — 

 A. Laveran and A. Pettit use a peptone-salt medium, which is dis- 

 tributed in Roux's flasks and then sterilised. Into each is poured an 

 equal quantity of defibrinated rabbit-blood. As the cultures are only 

 successful when there is a thin layer of liquid, the flasks are laid flat in 

 the incubator, which is regulated for 21-22° C. The quantity of 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, etc. ; 

 (6) Miscellaneous. t C.R. Soc. Biol. Paris, lxviii. (1910) pp. 114-15. 



