ZOOLOGY AND BOTANY, MICKOSCOPY, KTC. 723 



Have Trypanosomes an Ultra-Microscopical Stage ? *— David 

 Bruce and EL R. Bateinan have made a number of experiments to teat 

 this. From five experiments it would appear that the blood or organs of 

 rabbits suffering from nagana does not contain ultra-microscopical forms 

 of T. brucei. From eleven experiments it seems that the blood of nagana 

 rats, filtered through a Berkefeld filter, is not infective. From other 

 experiments it may be concluded that the blood of white rats suffering 

 from nagana, and treated for varying times with antimony salts, does not 

 contain ultra-microscopical forms of T. brucei. Cultures of T. lewisii on 

 blood-agar do not give rise to ultra-microscopical forms which are capable 

 of passing through a Berkefeld filter. The final conclusion arrived at 

 is that neither T. brucei nor T. evansi develop in the body of animals 

 forms so small as to be capable of passing through the pores of a Berke- 

 feld filter, and that in cultures of T. lewisii on blood-agar such small 

 forms are also absent. 



Budding in Acineta gelatinosa.t — B. Swarczewsky observed the 

 formation of amoeboid buds of various sizes, moving actively by pseudo- 

 pods, and fixing themselves after liberation to the stalk of the parent. 

 This is quite a different mode of budding from the production of 

 " ciliospores " with peritrichous cilia which has been described by various 

 observers of the Acineta?. 



* Proc. Roy. Soc, Series B, lxxx. (1908) pp. 394-8. 

 t Biol. Centralbl., xxviii. (1908) pp. 441-5 (8 figs.). 



