THE AMERICAN T.OBKTUR. 37 



Boeck asserts (20) in liis history of the Norwegian lobster fishery, that a real act of 

 copulation takes place, the male placing its double male member (modified appendages 



of the first abdominal somite) into the outer genital openings of the female, and 1 hat 

 the eggs are impregnated while they are yet in the ovary. 



Fraiche (70) says that the union of the sexes takes place in the fall of the year 

 (Oetober and November) for the common and Norwegian lobsters, and in the case of 

 the former species extends into winter: 



As with the crayfish, the sexual act is accomplished belly to belly, aud so closely and firmly do 

 thov clasp each other, that, if taken from the water at this period, it is with difficulty that they can 

 be separated. 



He thinks that the seminal fluid is introduced directly into the oviducts, and 

 says that the sides of the abdomen secrete a viscous substance which incloses the 

 eggs and attaches them to the body of the female. 



The question, How is the fertilization of the eggs effected in Crustacea? is one 

 which has been asked by naturalists from the days of Aristotle down to the present 

 century, and it has received the most varied and contradictory answers. A brief 

 account of the history of opinion on this subject has been given by Brocchi in his 

 thesis on the male organs of the decapod Crustacea, published in 1875 (25). One 

 source of difficulty lay, as recent studies have proved, in supposing that the process 

 was essentially the same in both Macrura and Brachyura. 



Porzio 1 and Oavolini (36) * among the older writers, as Brocchi shows, had (dearer 

 ideas upon this question than their immediate successors. Thus the Neapolitan 

 physician, Porzio, says, in his study on the lobster: 



Organa anteni propagations et generationis sic constructs, sunt, ut facilem non inveniam 

 rationem qua maris semen, in femime corpus ejaculari, infundi, vel introiri possit. 



Oavolini also remarks in his memoir on generation, published in 1787, that — 



The Crustacea copulate face to face, with the penis on the outside of the body; there is no intro- 

 mission, for the papilla which we have shown to he present on the base of the last jiair of legs can 

 scarcely serve to make a passage for the semen; the eggs are glued to the hairs of the female and are 

 bathed in the semen (36). 



Milne Edwards (58) in his Histoire Naturelle des Crustaces, published in 1834, 

 expressed some true ideas upon the reproductive processes in the Crustacea which were 

 not comprehended by many subsequent writers. At the same time he falls into errors 

 in regard to certain organs and their functions. He says that the first two pairs of 

 abdominal appendages in the male, which are often so different from the following 

 pairs, seem to serve as exciting organs in the act of reproduction, but that naturalists 

 have been mistaken in regarding them as representing the penis. In many cases, as in 

 Gegarcinus, their size would make it impossible for them to penetrate into the vulva, 

 and he says " we have proved, by direct observation, that in others it is the lower end 

 of the efferent canal which is alone introduced into the body of the female." These 

 appendages apparently assist in directing the penis toward the vulva, and possibly in 

 exciting the latter. (See note 1, p. 39.) He calls attention to the important fact that 

 in the Anomura and Macrura there is no copulatory pouch such as he had discovered 



1 1 have been unable to consult the origin;il works of these writers, and give the quotations from 

 them on the authority of Brocchi and Cano. 



