ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 331 



Trichomonas and Megastoma in Human Intestine.* — A. Ucke has 

 observed organisms in fresh fasces which he is inclined to regard as 

 stages in the development of Trichomonas. Besides the typical pear- 

 shaped organism, pointed posteriorly, with three flagella anteriorly, 

 undulating membrane, nucleus and vacuole, there were the following 

 phases : — The pear-shaped body is rounded off, and becomes oval. The 

 vacuole increases in size and the protoplasm is crowded into the 

 periphery. After the whole has become spherical the protoplasm is 

 collected at two opposite poles, whilst it thins out in the equatorial 

 plane. Here there begins a segmentation, which gradually increases 

 and leads to the segmenting off of two spherical but smaller bodies of a 

 signet-ring form. It is regarded as probable that further division goes 

 on. Out of 188 cases examined, the author found 9 infected with 

 Megastomum entericum, which occurred in both vegetative and encysted 

 forms. 



Biology and Affinities of Spirochsetae.f — H. B. Fantham discusses 

 the movements, structure, and general affinities of Spirochceta {Trypano- 

 soma) balbianii Certes and Spirochceta anodontm Keysselitz. The 

 motion of these organisms is resolvable into at least two components — 

 (1) a vibratory motion of flexion of the body mainly for progression ; 

 and (2) a spiral or corkscrew movement of the body as a whole, due to 

 the winding of the membrane. The membrane is a spirally wound 

 lateral extension of the ectoplasmic periplast. It is characteristic of the 

 genus Spirochceta as now defined. Only asexual modes of multiplica- 

 tion, principally by longitudinal fission, are known with certainty. 

 Spirochetes are regarded as having affinities both with bacteria and 

 the Protozoa ; they are undoubted protists. The author is inclined 

 to accept the protozoan nature of these organisms, and considers that a 

 provisional new class of the Protozoa, viz. Spirochaetacea, might be 

 instituted for their reception when our knowledge of them is a little 

 more extensive. 



* Centralbl. Bakt. Parasitenk., Orig., xlv. (1907) pp. 231-3. 



t Quart. Journ. Micr. ScL, lii. (1908) pp. 1-73 (3 pis. and 11 figs.). 



