7176 Unusual Modes of Gestation in 



was unable to learn anything with regard to the transfer of the ova 

 from the genital orifice to the point of their attachment. The only 

 organ which seems in any way adapted to such a purpose is the slen- 

 der and flexible tail, terminated by a delicate caudal fin. It is pos- 

 sible that the eggs may be deposited on the bottom of the river, and 

 subsequently attached by pressing the under side of the body upon 

 them. 



In those individuals where the ova were still in the ovary, but 

 approaching maturity, the integuments of the under side of the body 

 gave no other indications of the changes about to take place than of 

 being quite vascular ; the skin was perfectly smooth, no " pores" 

 were visible, but a large vessel was seen emerging from the region of 

 the liver, and, descending along the median line, gave off branches 

 quite freely to the integuments. This may have some relation to the 

 future development of the pedicles which support the eggs, and per- 

 haps to the nutrition of the embryo, as will be adverted to hereafter. 



In all the specimens which I have had an opportunity of examining 

 the eggs were either somewhat advanced or quite mature ; so that no 

 observations could be made on the earlier conditions of the egg and 

 the formation of its pedicle. The pedicle is a flexible outgrowth from 

 the common integuments, is about two lines in length, is attached to 

 the skin by a slightly expanded base, and spreads out at its summit 

 into a shallow cup or " cupule" for the support of the egg. It is com- 

 posed almost entirely of fibrous tissue, invested with a layer of tes- 

 sellated epithelium. In some instances, when the eggs were but little 

 advanced, numerous fusiform cells were detected among the fibres. 

 It is vascular, two or three vessels reaching to the cup, where they 

 ramify and form a somewhat extended capillary plexus. 

 , , The eggs vary according to the degree of development, from the 

 0*09 to 015 of an inch in diameter, and are covered with an external 

 homogeneous membrane, containing minute punctiform depressions ; 

 within this is a second, of a brownish colour, and composed of epi- 

 thelium. The embryos which were the most advanced, and just ready 

 to hatch, had not as yet completely absorbed the yolk, and were 

 coiled up within the membranes, which, in consequence of the irregu- 

 larities of the mass formed by the embryo, had no longer a spherical 

 form. 



• The eggs are retained in connexion with the cup apparently by 

 adhesion alone, for as soon as the foetus escapes the egg-membranes 

 become very easily detached from the pedicle, and this last, as shown 

 by some of the specimens, undergoes absorption. fyiiicrn.v. 



