

59.13.15: 53.5 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE 



MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD 



COLLEGE. E. L. MARK, DIRECTOR. 



No. 132. 



THE EARLY DEVELOPMENT OF LEPAS. A STUDY OF 

 CELL-LINEAGE AND GEEM-LAYERS. 



BY MAURICE A. BIGELOW. 



WITH TWELVE PLATES. 



FROM THE BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY 

 AT HARA-ARD COLLEGE, VOL. XL. No. 2. 



CAMBRIDGE, MASS., U.S.A. 

 JULY, 1902. 



