326 KOFOID AND SVVEZY. 



axostyle approaches and proceeds (PI. 3, Figs. 31-35, PI. 4, Fig. 30) 

 the nuclei assume a balanced relation (Fig. 31) and move into 

 close contact with the anterior ends of the new axostyles (Fig. 34) 

 which they retain throughout all of protean activity which precedes 

 the final separation of the daughter cells (PI. 4, Figs. 36-40, Fig. ¥). 



Previous accounts of the fate of the parent axostyle and of the origin 

 of the new axostyles have been in a state of contradiction and con- 

 fusion. According to Prowazek (1904) who first described mitosis 

 in trichomonads {Triclwmasiix Jacertae) the old axostyle disappears 

 and the new ones form out of the organ which we have called the 

 paradesmose which finally divides at its middle into 'the two new 

 axostyles as the daughter cells are separated. According to Grassi 

 and Foa (1904) in the division of Jocnin annectans the paradesmose 

 (fuso) is involved in the formation of the new axostyles as their central 

 cores and the old axostyle (mestola) is dispersed. E\idence of the 

 behavior of the two organs involved is insufiicient in just that period in 

 Jocnia in which division of the axostyle and disappearance of the 

 paradesmose takes place in Tnchomonas. Conclusive as their evi- 

 dence presented seems as to the correctness of their interpretation in 

 Joenia, it is highly desirable that these critical stages be reinvestigated 

 to see if a correlation with our results in Trichomonas may not be 

 possible. 



\A'enyon (1907) is the only author whose conclusions regarding the 

 origin of the axostyle in mitosis accord with ours. He states that it 

 " divides by longitudinal division and is the last part of the animal to 

 divide (pi. XI, fig. 3). In later stages it is seen extending tlirough 

 the body of the long drawn out animal from the neighborhood of one 

 nucleus to that of the other (pi. XI, figs. 15, 21). Ir the final stage, 

 two animals are attached simply by this organ, which finally gives 

 way, leaving the characteristic pointed ends." It is unfortunate 

 that none of his figures supports his views as to division and that his 

 context indicates a possible confusion of paradesmose and axostyle. 

 He notes the fiber between the daughter blepharoplasts in early mitosis 

 (his figs. 2, 4, 10, 11) but does not distinguish it from the axostyle in 

 later stages. 



Hartmann and Prowazek (1907) state with regard to trichomonads 

 {Trichomasiix laccrtae) that the axostyle is formed from the " Caryosom 

 des Amphinuclolus " but, as Dobell says, there is no foundation for 

 this statement certainly not in Prowazek's own (1904) observations, 

 and none whatever in our own data, for we have shown that the 

 blepharoplasts are persistent organs having nothing to do (in the 



