462 WINTERTON C. CURTIS, 



It was my great privilege to pursue a course of graduate study 

 under the guidance of the late Dr. James Ingraham Peck of Williams 

 College and this study of anatomy was undertaken at his suggestion 

 to aid in work of his own upon spermatogenesis in certain Planaria, 

 which his death left unfinished, but which it is my purpose at some 

 future time to complete. It is with the sincerest gratitude and ap- 

 preciation that I acknowledge the aid and suggestion he gave me 

 throughout the work of this paper. 



Williams College, December 1898. 



