THE EMBRYOLOGY OF THE AMERICAN 

 LOBSTER. 



HERMON CAREY BUMPUS. 



The observations embodied in the following paper were made 

 at intervals during the years 1889 and 1890, at the Marine 

 Biological Laboratory, Wood's Holl, and at Clark University, 

 Worcester, Mass. 



I would express my gratitude for the many helpful sugges- 

 tions and valuable assistance that the director of the Laborato- 

 ries of both institutions, Dr. C. O. Whitman, has most freely 

 offered. 



At the Marine Laboratory unlimited facilities have been 

 offered for collecting and preparing material, while the new 

 outfit for morphological work at Clark University has proved as 

 valuable as it is complete. 



The American lobster (Homarus americainis, Milne-Edwards) 

 inhabits the Atlantic coast of North America from Labrador to 

 Delaware, extending its bathymetrical range from low-tide mark 

 to a depth of from fifty to eighty fathoms. 



Years ago excessively abundant and not infrequently reaching 

 a weight of twenty pounds, the inordinate demands of the mar- 

 ket have not only rendered the animals much less abundant, but 

 have also reduced them in size, the greater number of lobsters 

 now caught averaging less than two pounds in weight. It was 

 partly with the idea of intelligently coping with this serious 

 destruction that the following observations were undertaken. 



Breeding. 



Data taken from a large number of individuals show that the 

 females do not ordinarily bear eggs (externally) until they have 

 reached a length of 25 cm., though it is an interesting fact 

 that many females are impregnated at an earlier date, when 



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