136 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



bryos loosely contained in the ovarian pouches when no trace of the egg- 

 membrane could be seen within the tissues of the ovniies in the shape 

 of a corpus luteum or a Graafian vesicle. Whatever be the case, numerous 

 eggs or embryos may be observed within one pouch. The young thus 

 remain together until grown to a considerable size, when, filling up the 

 space in a more compact manner, the ovarian membranes, in their 

 nature very expansive, will extend a fold between each embryo. In 

 this manner every individual young, when removed sideways from the 

 ovary, appears to the operator as though inclosed in a separate cavity, 

 pouch, or follicle of the ovary, whilst in reality the membranes may be 

 stretched out or extended, and the entire progeny loosened from all 

 adherence or connection with them. 



"The male organs of generation consist of two spermaries, aright 

 and a left, perfectly independent from one another, having each its sep- 

 arate duct, discharging their contents into an elongated cloaca, into 

 which the bladder likewise empties its contents. This cloaca commu- 

 nicates with the exterior by a subcircular opening, the edge of which 

 is rather protruding. Such is that apparatus, the isame in its general 

 structure as in the other osseous fishes. There is no sheath inclosing 

 the two spermaries, and this fact throws considerable light upon the 

 morphology of the ovaries ; the latter being, in fact, two in number, but 

 so closely connected together as to simulate a single orgau. Thus the 

 general disposition, not the plan of structure, of these organs is adapted 

 to the mode of reproduction ; a single sheath being a more simple 

 adaptation than two, one for each ovary. 



" How the mechanical act of fecundation takes place we are not pre- 

 pared to say from direct observations ; the eggs themselves must be 

 fecundated within the ovarian sheath ; a copulation of some sort is, 

 therefore, required, and it is not improbable that at this period the 

 eggs have dropped from the ovarian membranes into the pouches or 

 spaces between these membranes in which they are freely floating." 



Then follow some observations on the development of the embryos 

 which are to a great extent erroneous, the " abdominal bag," alluded 

 to as the yelksac, being probably the same as what I have determined 

 to be the greatly hypertrophied hind-gut which protrudes from the ven- 

 tral aspect of the body of the embryos. The cleft of the mouth, it is also 

 stated, is not apparent at the time the fins began to grow out. This is 

 also to be seriously doubted, and is a statement which probably rests 

 upon defective observation, as I find the vent to be perforate at the time 

 the embryos are an inch in length. 



Farther on Dr. Girard, speaking of the embryos of Ditremajachsoni, 

 six to seven tenths of an inch long, " The yelk-bag was still to be ob- 

 served in the shape of a hernia under the abdomen." 



In Emhiotoca persjncabilis, Girard states, op. cit., page 179, that " a 

 female on being opened was found to contain about eighty young of 

 an average size of half an inch, the whole embryo consisting of cells 



