ZOOLOGY: KOIFOID AND SWEZY 
321 
move to the poles of a spindle at each of which a centrosome formed by 
the division and polar migration of the parent organelle is found, is 
essentially mitotic rather than amitotic. 
The conclusions drawn are: 
(1) Cell division in trichomonad flagellates is a true mitosis with dif- 
ferentiated chromosomes (five in Trichomonas augusta), which spKt 
longitudinally prior to their location in the equatorial plate. 
(2) The nuclear membrane persists throughout mitosis. The bleph- 
aroplast which is connected to the flagella, rhizoplast, chromatic margin 
and basal rod of the undulating membrane, and to the axostyle, after 
division usually gives rise by division to a polar centrosome and an ad- 
jacent basal granule which alone retains connection with the extra- 
nuclear apparatus including the paradesmose. These two fuse again to 
form the daughter blepharoplasts. 
(3) The paradesmose between the migrating blepharoplasts is extra- 
nuclear at all times, disappears after nuclear division, and does not give 
rise to the axostyle. Since this connecting strand Hes outside of the 
nuclear membrane and connects basal granules and not centrosomes, 
it should not be called centrodesmose or central spindle, but rather 
the paradesmose. 
(4) The axostyle spHts longitudinally and thus forms the two daugh- 
ter axostyles. These do not grow out as new structures in Trichomo7ias 
augusta. It and the chromatic basal rod (homologous with the para- 
basal chromatic structures of JanickiO may be regarded as derivatives of 
the blepharoplast, homologous with flagella but intra-cytoplasmic. 
^ Dobell, C. C, Researches on the intestinal Protozoa of frogs and toads. Q. J. Microsc. 
Set., London, 53, 201-277, pis. 2-5 (1908). 
2 Prowazek, S., Untersuchungen Uberemige parasitische FlageJlaten. Arb. Gesundhtsamt., 
Berlin, 21, 1-41, pis. 1-4 (1904). 
3 Martin, C. H. and Robertson, M., Further observations on the caecal parasites of fowls. 
Part I. Q. J. Microsc. Sci., London, 57, 53-81, pis. 10-14 (1911). 
* Kuczynski, M. H., Untersuchungen an Trichomonaden. Arch. Prot., 33, 119-204, pis. 
11-16 (1914). 
^Montgomery, T. H., The spermatogenesis of an hemipteron. /. Morph., Boston, 22, 
731-815, pis. 1-5 (1911). 
^ Wenyon, C. M., Observations on Protozoa in the intestine of mice. Arch. Prot., Suppl. 
V. 1, 169-201, pis. 10-12 (1907). 
^ Janicki, C. Bemerkungen zum Kernteilungsvorgang bei Flagellaten namentlich bei 
parasitischen Formen. Verh. Nat. Ges. Basel, 23, 82-111, 8 figs. (1912). 
