137 



The Development of the Spermatozoid of Chara. 



By D. M. Mottier. 



(Abstract.) 



The spermatozoid of Chara fraglUs is a spiraUy-coiled body con- 

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

 the blepbaroplast, 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 blepbaroplast 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 broader and thicker and terminates bluntly. In cross section the 

 blepbaroplast is crescentic, being convex on the outside and concave 

 within. With the 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 blepbaroplast 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 blepbaroplast 

 might develop as described 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 attached some distance back of the 

 anterior extremity of the blepbaroplast. Their origin was not traced 

 to a centrosome-like body, but they seemed to grow directly from the 

 thread-like blepbaroplast. 



Contribution to the Flora of Indiana. 



By Stanley Coulter. 

 (By title.) 



