PAPERS ON BOTANY 141 



development of the blepharoplast precedes the change in form 

 of the nucleus. During this process the nucleus and cytoplasm 

 do not seem to be sharply separated by the nuclear membrane, 

 but there are indications of diffusion from one to the other. 

 The blepharoplast and nucleus continue to lengthen and fuse 

 more closely, at last becoming indistinguishable, and eventually 

 forming a long slender coiled almost filiform band or cord 

 pointed at both extremities. The blepharoplast may be seen 

 protruding for a short distance as a delicate filiform thread 

 from one extremity of the sperm which we may call the an- 

 terior end. Attached near the tip of the blepharoplast are 

 two long very delicate cilia. A vesicle, of granular cytoplasm 

 and perhaps some nuclear material, within the coiled body of 

 the sperm, disappears as the sperm reaches maturity, doubtless 

 being absorbed by- the main body or used up in protoplasmic 

 activity, perhaps both. 



To secure a common answer to the question of the origin 

 and nature of the blepharoplast seems quite difficult. Two 

 investigators, Ikeno and Bolleter, have described the ble- 

 pharoplast as originating in the nucleus, and passing out into 

 the cytoplasm through the nuclear membrane in the following 

 manner. Prior to the last division of the spermatogenous 

 tissue in the androcyte mother cell referred to above, a body 

 separates from the chromatin structure and passes through 

 the nuclear membrane into the cytoplasm. Here it divides 

 and the two daughter bodies move to opposite sides of the 

 nucleus and function as centrosome like bodies during spindle 

 formation and the division of the nucleus. Each of these two 

 daughter bodies persists in its respective cell, or androcyte, 

 and functions as the blepharoplast. The figures of Ikeno and 

 Bolleter scarcely present convincing evidence that any par- 

 ticular body which is first shown within the nucleus is identical 

 with the particular body later seen outside the nucleus. 



Others have described the appearance of the centrosome 

 like bodies at the poles of the last division and the persistence 

 of these bodies, each one in its respective androcyte, where it 

 functions as a blepharoplast. Still others report centrosome 

 like bodies during the last as well as earlier divisions of the an- 

 theridium, but fail to discover genetic continuity of these 

 bodies from one cell generation to the next. 



