TRANSACTIONS OF SECTION D. 741 



TUESDAY, SEPTMIBER 8. 

 Joint Meeting ivilh Section /. 

 The following Papers were read : — 



1 . Binomics of Tsetse Flies. By R. Newstkad. 



It is just seventy-eight years since Wiedemann published the first authentic 

 description of a tsetse fly, and it was this author also who in 1830 erected the 

 genus Glossina, basing his description on a single specimen of O. longipalpiSf 

 captured at Guinea or in the maritime region of West Africa, and now pre- 

 served in the Natural History Museum at Vienna. In the same year, though at 

 a somewhat later date, Robineau-Desvoidy overlooked Wiedemann's work and 

 erected the genus Nemorhina for the reception of Glossina palpalis, which is now 

 known as having the widest distribution of all the members of this remarkable 

 genus. In 1849 Mr. F. Walker described G.fusca, and in 1850 Professor Wedge- 

 wood gave the diagnosis of G. morsita7is and G. Tachinoides. Austen described 

 G. pallidipes and Bigot G. pallicera. Recently Mr. Newstead has also described 

 a species taken at Leopoldville by (the late) Dr. Button and Dr. J. L. Todd. 

 Referring to the life-history of these flies, Mr. Newstead pointed out that a 

 single female produced one fully matured larva at a time, and at intervals of from 

 four to ten days. The habitat for the pupa was first discovered by Dr. Bagshaw 

 among the roots of banana, but the author had subsequently found them, an inch 

 to an inch and a half below the surface, among the fallen leaves of a deciduous shrub 

 belonging to the genus Alophyllus, as well as between the buttressed roots of a 

 species of ficus, &c. The distribution, habitats of the flies, and other matters 

 were dealt with, special reference being made to the structural characters of these 

 insects. 



2. Cultures of Amcebce. By J. W. W. Stephens, 31. D. 



The medium at present in use for the cultivation of amoebae is that devised by 

 Muegrave and Clegg, viz. : — 



Agar .... 20-0 grammes. 



Nail .... 0-3-0-5 „ 



Beef extract . . . 0-3-0'5 „ 



Distilled water . ^ 1000 c.c. 



The alkalinity should be one per cent, to pbenopthalein. The optimum tempera- 

 ture is 20°- 25° C. No growth is obtained under anaerobic conditions. 



Mode of Isolation of Amoeba. — The faecal material is streaked on agar poured 

 out in plates in the ordinary way. Some authors advise ^/si smearing the plate 

 with cultures of various bacilli obtained from the stool in question. The reason 

 for this latter procedure is that amoebae are symbiotic with bacilli, and a selection 

 of bacilli is offered in order to increase the chance of a successful result. 



Pure Mived Cultures. —St&itiag from an impure culture of amoebae and bacilli 

 obtained from the gut, the plate is examined with a low power of the microscope and 

 a single isolated amoeba is selected. This is then enclosed with a ring of carbcl- 

 vaselme (Walker), so as to prevent the amceba wandering out or others wandering 

 into the ring. When this amceba has sufficiently multiplied it is transferred 

 to another plate, so that we have a culture of one species of amoeba with several 

 bacilli (viz., those of the gut). In order to get a pure mixed culture, a pure 

 culture of a particular bacillus (.r) is inoculated in concentric rings on a fresh 

 plate ; the impure culture is inoculated in the centre, and as the amceba wanders 

 over the plate it leaves behind its bacilli (obtained from the gut) and is found with 

 the periphery of the plate, now, with the pure culture of bacillus (.i), giving the 

 pure mixed culture. 



