Proceedings of the American Academy of Arts and Sciences. 

 Vol. XLIII. No. 3. — Juxe, 1907. 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE 

 MUSEUM OF COMPARATIVE Z(JOLOGY AT HARVARD COLLEGE, 

 E. L. MARK, DIRECTOR.— No. 190. 



MATURATION STAGES IN THE SPERMATOGENESIS 

 OF VESFA MACULATA Linn. 



By E. L. Mark and Manton Copeland. 



