Bulletin of the Museum of Comparative Zoology 

 AT HARVARD COLLEGIA. 



Vol. XL. No. 2. 



THE EARLY DEVELOPMENT OF LEPAS. A STUDY OF 

 CELL-LINEAGE AND GERM-LAYERS. 



By Maurice A. Bigelow. 



With Twelve Plates. 



CAMBRIDGE, MASS., U. S. A. : 



PRINTED FOR THE MUSEUM. 



July, 1902. 



