200 M. Coste on the Habits of some Marine Animals. 



The results of these first observations are sufficient to prove 

 the veracity of the historians of antiquity as regards the marvel- 

 lous stories which they have transmitted to us of the spectacles 

 furnished by the nomenclators in the marine piscin?e of Lucullus, 

 PoUio, and the orator Hortensius. They prove that these state- 

 ments^ far from being fables_, as people have been disposed to 

 think, are really the simple expression of the truth. 



The Crustacea enclosed in the compartments of the vivarium 

 have also furnished us with interesting observations upon their 

 mode of copulation, their oviposition, and their metamorphoses. 

 In all the Brachyurous Decapods which we have been able to 

 observe, such as the common Shore Crab [Cancer Manas, Linn.), 

 the Xanthofloridus of Leach, the x\rched-fronted Swimming-Crab 

 {Portumis Rondeleti, Ilisso), the Marbled Swimming-Crab {Por- 

 timus marmoreus, Leach), the hairy Porcelain Crab {Porcellana 

 platTjcheles, Penn.), the Spider-Crab [Maia Sqimiado, Uevhst), the 

 common edibleCrab {Cancer Paf/urus,Linn.), the minute Porcelain 

 Crab [Porcellana lonyicornis, Lat.), &c., we have seen the male, 

 by the agency of his copulatory styles, and through the sternal 

 apertures, deposit the semen in a dilatation of the oviduct, a 

 dilatation situated at the lower extremity of that canal. 



In the Shore Crab (C. Manas) the semen accumulated 

 in this place of deposit becomes solidified and moulded there, 

 acquiring the consistence of coagulated wax. It remains in this 

 state for about a fortnight, after which it slowly becomes lique- 

 fied, in order that the spermatozoids, which are then disaggre- 

 gated and suspended in the fluid resulting from this liquefac- 

 tion, may ascend to the ovaries, — a phsenomenon which lasts not 

 less than two months. The ovarian eggs, which at the moment 

 of copulation were still in the microscopic state, increase in pro- 

 portion, but do not arrive at complete maturity until long after 

 the complete disappearance of the seminal fluid. We are ob- 

 serving, in closed cases, specimens which copulated three months 

 since, and which have not yet deposited their eggs. The dis- 

 section of some of these has shown us that the eggs are far from 

 having attained the degree of development required for their 

 expulsion. This fact proves two things: — 1. That in these 

 species the fecundation is ovarian ; and 3. that when submitted 

 to the influence of the male element, the ova are far more distant 

 from the period of their maturity than is the case in any of those 

 observed in other classes. 



In the Long-tailed Decapods [Macrura) the semen is not in- 

 troduced into an internal pouch, but it is poured out upon the 

 sternum in the vicinity of the orifices which lead to the oviducts. 

 In some, such as the Lobsters and Spiny Lobsters, it is spread 



