112 BOTANICAL GAZETTE [august 



growing out directly from it. Henneguy (44) even observed cilia 

 attached to the centrosomes of the karyokinetic figure in the sper- 

 matocyte of an insect. 



In comparing the structures of the plant spermatozoid with those 

 of the animal spermatozoon, Belajeff (5) regarded the blepharo- 

 plast, the thread to which it elongates, and the cilia of the former 

 as homologous with the centrosome, middle piece, and tail, respec- 

 tively, of the latter. The blepharoplast of Chara is included in this 

 comparison in spite of the apparent difference in its mode of origin. 

 Strasburger (80), although agreeing that the body at the base 

 of the flagellum of the animal sperm is a centrosome, homologized 

 only the axial filament of the flagellum with the blepharoplast. 

 This comparison leaves both the cilia of the plant spermatozoid 

 and the centrosome of the animal spermatozoon without counter- 

 parts, though a complete homology of this sort is by no means a 

 necessity. The behavior of the centrosomes in the spermatid of 

 Helix (Korff 58) has made it evident that the axial filament of 

 the flagellum is not a differentiation of the cytoplasm, starting at the 

 centrosome, but is made up of the centrosome substance itself. 

 Thus in comparing the blepharoplast to the axial filament its 

 centrosome relationship is not entirely avoided. In a discussion of 

 this question E. B. Wilson (92) regards the work of Shaw and 

 Belajeff on Marsilia as establishing beyond question the identity 

 x>{ the blepharoplast and the centrosome. He considers the 

 comparison of Belajeff as justified and concludes that "the facts 

 give the strongest ground for the conclusion that the formation of 

 the spermatozoids agrees in its essential features with that 

 of the spermatozoa. . 



The deeply staining bodies at the base of the flagella in other 

 ciliated animal cells have also been investigated for further light 

 upon this problem. That they correspond to centrosomes has been 

 rendered highly probable by the work of Henneguy (44) and 

 Lenhossek (60), while Studnicka (81) has obtained evidence 

 apparently in favor of a contrary interpretation. This question 

 must remain with others for further researches to clear up. 



In the meantime it should be borne in mind that whatever 

 interpretation is finally put upon the cilia-bearing structures of any 





