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3. The Reproduction of the Lobster. 



By Francis H. Herrick, Adelbert College, Cleveland, Ohio, U.S.A. 



eingeg. 30. Mai 1894. 



The breeding habits of the lobster [Homarus americanus) is a 

 subject about which many conflicting statements have been made. 

 These have resulted from insufficient observation, while much has also 

 been written in ignorance of ascertained facts. 



The questions of most immediate interest are; 1) When are the 

 eggs laid; 2) what is the length of the reproductive period, or how 

 often are the eggs produced ; 3) what is the law of production , or the 

 relation between the number of eggs and the size of the animal pro- 

 ducing them; 4) how are the ova fertilized; 5) when do the young 

 hatch; 6) what is the law of survival of the larvae? 



I have recently gathered some new facts which bear particularly 

 upon the first of these questions, and clear away much obscurity which 

 has surrounded it. Before giving these I will first point out the con- 

 dition in which this subject has remained up to a very recent date ^. 



It at first seemed probable that the breeding season of the lobster 

 was not limited to a definite season of the year, but further study con- 

 vinced me that this conclusion was erroneous, and in a paper published 

 in 1891 the following statement was made »The spawning season is 

 confined to the summer months, and the eggs which are then laid, are 

 carried by the female throughout the fall, winter and spring, and are 

 not hatched under natural conditions until the following summer« 

 (Notes on the Habits and Larval Stages of the American Lobster, 

 Johns Hopkins University Circulars, Vol. 10. No. 88. May, 1891). 



Bump us (Journal of Morphology, Vol. 2. Sept. 1891) tells us in 

 his careful paper on the embryology of the lobster, that »the eggs are 

 normally deposited during the months of July and August«, Eggs 

 collected in winter at Nahant »were almost invariably in the same 

 advanced stage of development — the eyes large and bright, the appen- 

 dages well outlined, and the yolk occupying but a fraction, perhaps 

 one third of the surface exposed«. Of hundreds of lobsters examined 

 in May 1890 at Woods Holl, Mass., »not a single one had eggs in early 

 stages of development (f. Verrill (Report upon the Invertebrate Animals 

 of Vineyard Sound etc. p. 745) affirmed that he had examined lobsters 

 with freshly laid eggs in December, and that the breeding season ex- 

 tended over a large part of the year. 



1 See »The Habits of the Lobster, and their Bearing on its Artificial Propo- 

 gation«. (Bull. U. S. Fish Commission, Vol. 13. 1893.) 



