PRODUCTION OF SPERMATOZOA IN ROTIFERS. 315 



Hudson and Goss. 



'86 The Rotifera. Vols. 1-2. Longmans, Green, and Company. 



November j. In some recent and more careful studies on the 

 spermatogenesis of Brachionus mulleri it has been determined 

 that the bodies which have been designated as normal sperma- 

 tozoa are only the detached tails of these spermatozoa and are 

 not the complete cell. When the males are compressed under a 

 cover glass the tails become detached from the heads of the 

 spermatozoa while inside the body of the males and then are 

 immediately extruded and remain in an active state for a con- 

 siderable length of time. This fact was not observed by Hudson 

 and Goss as is shown by their plate 27 nor by myself until very 

 recently. 



As these motile tails resemble very closely the motile sperma- 

 tozoa of the other species of rotifers described in this paper it is 

 very probable that all the motile and supposedly complete 

 spermatozoa observed were also only tails. Whether the bodies 

 that were considered rudimentary spermatozoa are only tails of 

 such spermatozoa or are complete spermatozoa has not been 

 definitely decided. 



These new detailed facts do not, in the least manner, invali- 

 date the main issue of the paper in regard to the two classes of 

 spermatozoa and their ratio. Additional observations and data 

 derived from these recent studies will be published shortly. 



THE AUTHOR. 



