608 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
Ciliata of Geneva.* — M. Jean Boux has made a faunistic study of 
the ciliated Infusorians around Geneva, and has discovered seven new 
genera. 
Galvanotropism of Ciliated Infusorians.f — M. Henri Mouton, fol- 
lowing experiments of Yerworn and Ludloff, has shown that in an 
experiment with Paramsecium the current acts directly, and not through 
diffusible products formed near the electrodes. Other Infusorians (Col- 
poda ) showed in presence of products of the electrolysis at the kathode 
a negative chemiotropism, which in the immediate neighbourhood of the 
electrode exceeded the effect of the positive galvanotropism, though 
counterbalanced by it at a greater distance. 
Hew Species of Infusorians.^; — Mr. J. C. Smith continues his ac- 
count of new members of the Infusorial fauna of Louisiana, describing 
new species of Tetramitus, Enchelys, Tillina , Lembus, and Strombidin - 
opsis. 
Organism of Tsetse Fly Diseased — Mr. H. G. Plimmer and Prof. 
J. Hose Bradford have published a preliminary note on the structure 
and distribution of the organism found in the Tsetse fly disease, dis- 
covered by Major Bruce, and classed by him as a Trypanosoma , one of 
the Monadina (Flagellata). 
They describe the adult form, and its distribution in the body of 
normal and spleenless animals ; and they discuss the degrees of infec- 
tivity. 
Tentatively they sketch the life-history of Trypanosoma brucii. There 
is reproduction by division of two kinds, more commonly longitudinal, 
less frequently transverse. There is conjugation, consisting essentially, 
so far as the investigators’ observations go, in the fusion of the micro- 
nuclei of the conjugating organisms. Probably succeeding conjugation 
is the occurrence of forms in which the chromatin is broken up and 
diffused. The next stage is amoeboid ; but probably the flagellate forms 
may assume this phase apart from conjugation. The amoeboid forms, 
which are constantly seen in pro3ess of division, fuse or aggregate into 
plasmodia, which reach a large size in the spleen. From these again 
are given off flagellate forms which increase in size and become the 
ordinary adults. 
Pseudomonas stewarti.|] — Dr. E. F. Smith gives the following de- 
scription of Pseudomonas stewarti sp. n. isolated by Stewart from sweet 
corn. A motile rodlet with rounded ends, 0 • 5-0 • 9 X 1-2 fx ; one polar 
flagellum ; no spores observed ; found in the vascular bundles of corn 
(Zea mays) associated with a destructive disease of which it is probably the 
cause ; colour in the host-plant and in culture media yellow ; aerobe and 
potential anaerobe ; grows in all ordinary culture media with alkaline or 
acid reaction ; growth favoured by cane-sugar, grape-sugar, and galactose ; 
produces alkali ; reduces litmus slowly ; does not liquefy gelatin or 
blood-serum ; grows well at 25°-30° C. ; does not produce gas ; is sen- 
sitive to light, but does not die out quickly. 
* Rev. Suisse Zook, vi. (1899) pp. 557-636 (2 pis.). 
f Comptes Rendus, cxxviii. (1899) pp. 1247-9 (1 fig). 
X Trans. Amer. Micr. Soc., xx. (1899) pp. 51-6 (1 ph). 
§ Proc. Roy. Soc., lxv. (1899) pp. 274-81. 
|S Proc. Amer. Assoc. Adv. Sci., xlvii. (1898) pp. 422-6. 
