v^ ^ - 





59.13.15: 53.5 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE 



MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD 



COLLEGE. E. L. MARK, DIRECTOR. 



i in * 



No. 132. 



HE EARLY DEVELOPMENT OF LEPAS. A STUDY OF 

 CELL-LINEAGE AND GERM-LAYERS. 



BY MAURICE A. BIGELOW. 



WITH TWELVE PLATES. 



FROM THE BULLETIN OP THE MUSEUM OP COMPARATIVE ZOOLOGY 

 AT HARVARD COLLEGE, VOL. XL. No. 2. 



CAMBRIDGE, MASS., U.S.A. 

 JULY, 1902. 



