A ROTIFER. 33 



of the muscle bands which produce the movements of extension 

 and retraction. 



REPRODUCTION. No part of the reproductive system will be demon- 

 strated in our study, except, perhaps, masses of eggs forming inte- 

 riorly. The specimen you are studying is probably a female, for the 

 male is quite small and inconspicuous and is found only in the autumn. 

 The generations are produced parthenogenetically during the spring 

 and summer; the winter eggs require fertilization. These eggs remain 

 dormant during the winter and will stand drying up in the mud. In 

 this condition they may be transported from place to place by the feet 

 of birds and other higher animals. 



Exercise i. Draw one or more rotifers on a much enlarged scale, 

 showing all the details of structure you have been able to make out. 



