1908] YAMANOUCHI— SPERMATOGENESIS AND OOGENESIS 163 



published, according to which the blepharoplast has nothing to do 

 with the mitosis as a center of the mechanism of nuclear division, but 

 simply lies near the pole of the spindle. He does not regard the 

 blepharoplast as a centrosome. 



Belajeff's conclusions (7) in reference to Marsilia oppose those 

 of Shaw; for he believes that the blepharoplast always occupies the 

 pole of the spindle and functions as a centrosome during mitosis. He 

 claims that the blepharoplast in pteridophytes is homologous with 

 the centrosome. He figures the division of the centrosome or blepharo- 

 plast in the spermatid mother cell previous to the division of the 

 nucleus, and between the two separating daughter 'centrosomes or 

 blcpharoplasts a small central spindle is developed just as in certain 

 animal cells. 



Ikeno (45) considers the blepharoplast of Marchantia to be actu- 

 ally a centrosome, as shown by its behavior during mitosis. He 

 homologizes the Nebenkorper, the deeply staining body in the cyto- 

 plasm of the spermatid, with the blepharoplastoid of Shaw. Again 

 he (46) discusses the homologous nature of the blepharoplast and 

 centrosome in his paper entitled " Blepharoplasten im Pflanzenreich." 

 The Ncbenkern of Belajeff, he suggests, is homologous with the 

 deeply staining body (the Korperchen) in the spermatid of animals. 

 Last year Ikeno (47) reasserted his belief that the blepharoplast is a 

 centrosome. He thinks that the bodies now called blepharoplasts 

 may not all be homologous structures, but he holds that the blepharo- 

 plasts of pteridophytes, gymnosperms, liverworts, and myxomycetes 

 are of centrosome origin either ontogenetically or phylogenetically. 



The foregoing accounts of Ikeno confirm Belajeff's view regard- 

 ing the homology of centrosome and blepharoplast. Strasburger 

 (87) wrote at length on this subject seven years ago, and does not 

 accept Belajeff's view. He emphasizes the kinoplasmic character 

 of the blepharoplast, whether it be a differentiated region of the 

 plasma (as he believes for the zoospores of Vaucheria, Cladophora, 

 and Oedogonium), or a special development in the interior of the 

 cytoplasm (pteridophytes and gymnosperms). He thinks that all kino- 

 plasmic structures, bs they centrosomes, centrospheres, or blepharo- 

 plasts, hold a very close physiological relation to the structure of 

 the nucleolus, so that the blepharoplast might occupy the position 



