Chapter II.— REPRODUCTION. 



THE REPRODUCTIVE ORGANS. 



The breeding habits of an animal are not only of great scientific interest, but of 

 the utmost practical importance, in view of any experiments which we may under- 

 take in its artificial propagation. When this work was begun the breeding habits 

 of the lobster were very imperfectly understood, and until now no exhaustive study 

 of the subject has been attempted. In questions of this kiud, one may be led to 

 draw conclusions from too slender data, since an abundance of carefully attested 

 tacts gathered from a sufficiently wide area can be attained only with great difficulty. 



In the summer of 1891 I made as full a study as the time would allow of the 

 reproductive organs and habits of the lobster at Woods Hole, Massachusetts, and iu 

 the summer and fall of 1893 I was able to add to my knowledge of this subject by 

 materials gathered at different points along the northern Atlantic coast. 



The reproductive organs will now be briefly considered, reserving a description of 

 their structure and development for another part of this paper. (See Chapter X.) 



The ovaries, or "coral" as they are sometimes called, consist of two cylindrical 

 rods of tissue united by a transverse bridge in the upper part of the body, and are 

 immediately exposed upon opening the dorsal body wall. The uniting bridge of tissue 

 probably represents the first trace of a fusion, which is expressed in various degrees 

 in different Decapods. The ovarian lobes extend over about two-thirds the length of 

 the animal, from behind the head to the third, fourth, or fifth segments of the "tail," 

 and when approaching maturity are of a rich, dark-green color (plate 36, fig. 123; see 

 also plate 38). The ripe ovaries are so much swollen that they fill all the available- 

 space in the upper parts of the body-cavity. The bead-like eggs are clearly seen 

 through the thin ovarian wall, and when this is cut they flow out, if perfectly ripe, in 

 an uninterrupted stream. When the congested ovary is not mature the loosened eggs 

 stick together and can not be easily disengaged without injury. A female with eggs 

 approaching maturity can be readily distinguished by extending the translucent 

 membrane between the "tail" and carapace, through which the deep-green color of 

 the ovary is at once apparent, but since the eggs can not be pressed from the unyield- 

 ing body of the animal, there is no way of telling when these are ripe short of actual 

 dissection. 



The secondary organs of reproduction in the female are: (a) The oviducts, two short 

 membranous tubes, which lead from the ovaries to the exterior, and open,- one on each 

 side, upon the basal segments of the second pair of walking legs; (b) the copulatory 

 pouch or seminal receptacle, for storage of spermatozoa (plate 7, and plate 38, fig. 130), 

 situated between the bases of the third pair of walking legs; (c) cement glands, which 

 secrete the material by which the eggs are fixed to the swimming legs (plate 40. fig. 

 141, and plate 49, figs. 211, 212): (cl) the first pair of abdominal appendages, which 

 are so reduced iu size and modified as to be useless for swimming. 



P. C. li. 1895—3 



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