io8 BOTANICAL GAZETTE [august 



and is treated in the light of analogous phenomena in animals, much 

 of the apparent force of these objections is removed. 



In Marsilia, as Belajeff indicates in his fig. 7 (7), and in 

 Equisetum, the blepharoplasts are surrounded during the early- 

 stages by asters, though these are very weakly developed. When 

 they separate there appears a central spindle, forming with the 

 asters an amphiaster so characteristic of animal cells. In Equisetum 

 the radiations persist during the divergence of the blepharoplasts to 

 opposite sides of the cell, and those on the side toward the nucleus 

 remain as the achromatic portion of the karyokinetic figure. The 

 weakness of the other rays or their failure to remain seems to be a 

 matter of secondary importance in the light of spindle-forming 

 activity of this sort. Furthermore, the figures given by zoologists 

 indicate that the occurrence of an aster about the centrosome at the 

 spindle pole is by no means universal in animal cells. In discussing 

 this phase of the question Ikeno (54) cites the work of Meves and 

 Korff (65) upon the myriopod Lithobius forficatus, in which the 

 spermatocyte centrosomes lie at a considerable distance from the 

 spindle poles during mitosis. The figures given by Meves and 

 Korff are strikingly like those of Ginkgo (Hirase) and Cycas 



(Ikeno). 



It is true that the blepharoplast is, as a rule, limited to a single 

 mitosis, but here we must remember the case of Marsilia where it is 

 present during three, possibly all four, of the spermatogenous divi- 

 sions, and also certain liverworts in which a similar condition has 

 been reported. Webber accounts for the occurrence of blepharo- 

 plasts in all the spermatogenous cell generations in Marsilia by 

 considering the latter potential spermatozoids, and thus regards 

 the fact that they appear de novo in each cell generation only to 

 disappear at the close of division as a support to his theory of the 

 independent nature of the blepharoplast. If the cells between the 

 central cell of the antheridium and the final spermatids are held to 

 be potential spermatozoids, we should expect, as Webber points 

 out, blepharoplasts or their rudiments to be present occasionally. 

 Although these ideas are in accord with the conception of the 

 blepharoplast as an organ sui generis, at the same time it does not 

 seem to the present writer that they offer any necessary argument 



