137 



The Development of the Spermatozoid of Chara. 



By D. M. Mottier. 



(Abstract.) 



The spermatozoid of Cham frayUis is a spirally-coiled body con- 

 sisting of a nucleus and a specially differentiated part of the cytoplasm, 

 the blepharoplast, existing in the form of a thread, or band, bearing 

 two long cilia. The nucleus occupies the middle part of the sperma- 

 tozoid. The anterior end of the blepharoplast is thinner than the 

 posterior and tapers slightly toward the extremity. The two cilia are 

 borne some distance back of the anterior extremity. The posterior end 

 is bi'oader and thicker and terminates bluntly. In cross section the 

 blepharoplast is crescentic, being convex on the outside and concave 

 within. With tlie exception of a strip of granular substance along 

 the concave side of the posterior end, it is of a homogeneous structure. 

 The entire spermatozoid makes two and one-half or three spiral turns. 



The blepharoplast arises as a delicate thread-like differentiation of 

 the cytoplasm at the surface of the cell, extending some distance along 

 the cell from the nucleus and on opposite sides of the latter. It seems 

 to be a modification of the plasma membrane. No centrosome-like 

 body, or "Plasmahocker," was observed from which the blepharoplast 

 might develop as descril^ed by Belajeff, Strasburger and others. 



The nucleus is transformed from an elliptical or oval body, with 

 a hollow chromatin spirem, to a dense, homogeneous, sausage-shaped 

 structure making one spiral turn or more. 



The cilia were always found attaclied some distance back of the 

 anterior exti'emity of the blepharoplast. Their origin was not traced 

 to a centrosome-lilie body, but tliey seemed to grow directly from the 

 thread-like blepharoplast. 



Contribution to the Flora of Indiana. 



By Stanley Coulter. 

 (By title.) 



