DEVELOPMENT OF APYRENE SPERMATOZOA. 



paratively slow and is not long continued as it soon attaches 

 itselt by means of its tail-piece to the glass slide or other object 

 upon which it is being observed. As soon as this occurs the 

 contr.H -lion waves pass down both the membranes simultaneously 



v 



Initial magnification <>f 1.850 diamrt'i-. ii-.luo-cl one third. Fig. 



^:n>mbus bitubercttlatus. Fig. 2, apyrene spermato- 



ie form. Fii:. 3, -prrmatozoun of Lilturina nehulosj >lu .\ving the 



lout;, thin |n-iiiiati>rinin. Fig. 4, spermatozoon of L. anguliffm rho\\ing the 



1" MI 'i.it"iiiiiii -\vnlli-n aiti-r hi-ing in sea-water lor some time. Fig. 5. nur<e-cell 



1.1 /.. Mt-//i>.v(j with attaih'-il spermatozoa; drawing made from a living cell. 



and they Urome much shorter and faster. With tin- spermato- 

 zoon attached in this way, the membranes may continue to be 

 active for an hour or two. It very frequently happens, however, 



