ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 307 



and an adjacent basal granule to ■which flagella, paradesmose, and 

 parabasal are attached. These two granules re-unite. In its divisions 

 the blepharoplast shows no independent mitotic phenomena. It is not 

 a " kineto-nucleus," and its behaviour does not support the bi-nuclearity 

 hypothesis. The anterior blepharoplasts are shared, two and one 

 respectively, by the daughter blepharoplasts, and new outgrowths 

 complete the complement of each daughter organism. The chromatic 

 margin of the undulating membrane represents an intracytoplasmic 

 posteriorly-directed flagellum. It splits longitudinally to the lip of its 

 projecting end. The undulating membrane below it also splits. The 

 chromatic basal rod is the homologue of the parabasal body of 

 Parajoenia and the Trichonymphida as established by Janicki. The 

 new axostyles of the daughter organisms are formed by the longitudinal 

 splitting of the old axostyle from the anterior end. They are not 

 formed from the central spindle as maintained by Dobell, or anew as 

 claimed by Kuczynski. The axostyle is not primarily a skeletal 

 structure as usually supposed, nor an organ of fixation as described by 

 Kunstler and Kuczynski, but a locomotor organ used vigorously during 

 the amoeboid stage. During mitosis the organelles are subject to a 

 wide variation in location. Plasmotomy is long delayed after nuclear 

 mitosis, and during this period many widely varying positions are 

 assumed by the two daughter nuclei. Some of these may simulate 

 copulation. The plane of division is longitudinal. 



Multiple fission occurs in the trichomonad flagellates as a normal 

 phase of the life-cycle, and results in the formation of an 8-nucleate 

 Plasmodium or somatella. The observers have not so far been able to 

 relate it to a particular stage such as gametogenesis, or to the divisions 

 of a zygote. Three rapidly succeeding synchronous mitoses give rise to 

 2-4-8-nucleate plasmodia which are not encysted and remain very 

 active throughout the process. The plasmodium disintegrates into its 

 component members by the successive detachment of single merozoites. 

 The widespread occurrence of the stage of a multinucleate plasmodium 

 among these simple Protozoa is significant as an early step in the 

 evolution of the more permanent multinucleate and multicellular 

 aggregates which constitute the Metazoa. 



Pneumocystis carinii in Mice in England.* — Annie Porter 

 records the occurrence of this parasite in the lungs of a mouse in 

 England. The cysts are spherical or oval and from 4 /x to 6*5 //, in 

 diameter. Eight merozoites are finally formed within them. The 

 organism appears to be an independent parasite of the lungs of certain 

 Vertebrates and to be unconnected with any Trypanosome. 



Common Intestinal Protozoa of Man.f— C. M. Wenyon gives a 

 very useful account of Protozoa from the alimentary tract of man. 

 Some of these are at present not uncommon in soldiers who have 

 returned from the East. To the Khizopods belong the definitely patho- 



* Parasitology, viii. (1916) pp. 255-9 (8 figs.). 

 t Laucet, Nov. 27, 1915, pp. 1173-83 (1 pL) 



