1912] SHARP—SPERM ATOGENESIS IN EQUISETUM 95 



cilia-bearing band. In this paper Webber gives a very extensive 

 discussion of the morphological nature of the blepharoplast which 

 will be referred to later. 



Ikeno (51) expressed the opinion that the blepharoplast of 

 Ginkgo and the cycads is not only similar to a centrosome but is a 

 true centrosome, a view shared by Guignard (36). Soon after 

 this Ikeno's full account of gametogenesis and fertilization in 

 Cycas appeared (52) . In this paper it was shown that the blepharo- 

 plasts appear in the body cell, lie opposite the spindle poles during 



form 



manner similar 



Several years later the same writer published two papers 



m 



In 



former 



makes comparisons with analogous phenomena in animals, which 

 he believes sustain the homologies of Belajeff. He points out 

 that in Marchantia centrosomes are present in all the spermatoge- 

 nous divisions, while in other liverworts they appear much later, 

 and from this argues that the bryophytes show various stages in the 

 elimination of the centrosome. He strongly reasserts his belief 

 that blepharoplasts are centrosomes and speaks of the "Umwand- 

 lung eines Zentrosoms zu einem BleoharoDlast" in the development 



spermatid into a spermatozoid. The Hautsch 



& 



algae are also held to be ontogenetically or phylogenetically derived 

 from centrosomes. In the later contribution (55) he insists less 



strongly upon the mo 



them into three categ 



itity of all blepharoplasts, 

 (1) centrosomatic blepharo- 



plasts, including those of the myxomycetes, bryophytes, ptendo- 

 phytes, and gymnosperms ; (2) plasmodermal blepharoplasts, those 

 of Char a and some Chlorophyceae; (3) nuclear blepharoplasts, 

 found only in a few flagellates. 



The blepharoplasts of Microcycas (Caldwell ii) appear in the 

 cytoplasm of the body cell, often very close to each other. They 

 are surrounded by prominent radiations and lie opposite the spindle 

 poles through mitosis. At metaphase they have already broken 

 up and begun the formation of the spiral band. 



Chamberlain (15) observed in the cytoplasm of the body cell 



