550 



DR. DAVY ON THE TORPEDO. 



Fig. 4. Front view of the foetal Torpedo, showing a more advanced stage in the 

 development of the branchial filaments and electrical organs. 



Fig. 5, Front view of the foetal Torpedo at a more advanced stage, with the abdo- 

 men laid open to show, 

 A. The vitello-intestinal canal, connecting the yolk and intestine previous to 



the appearance of the internal yolk-vesicle ; 

 D. The intestine distended with yolk. 



Figg. 6 and 7- Foetal Torpedos further advanced, with the cavity of the abdomen 

 laid open, showing the internal yolk-bag, b, progressively augmenting, as 

 the external yolk-bag, a, is diminishing. 



Fig. 7. D. The intestine laid open below the stomach, e, showing the entrance of 

 the vitello-intestinal canal. 



Plate XXIII. 



The figures in this plate are intended to show the diminution and disappearance of 

 the external yolk-vesicle, and, with fig. 1. Plate XXIV., the diminution of the internal 

 yolk-vesicle. 



Fig. 1 . Front view of a young Torpedo, showing a further diminution of the exter- 

 nal yolk-bag. 

 Fig. 2. Ditto, showing the total disappearance of the external yolk-bag. 

 Fig. 3. Ditto, with the abdomen laid open, showing, 



B. The internal yolk-bag, of large size. 

 Fig. 4. A young Torpedo, six weeks old ; the cavity of the abdomen laid open, to 

 show, 

 B. The internal yolk-bag, considerably diminished in bulk, and its connexion 

 with the umbilicus almost absorbed ; 



D. The intestine, full of yolk ; 



E. The stomach considerably developed, but empty. 



Plate XXIV. 



Fig. 1 . A Torpedo, six months old ; the cavity of the abdomen laid open to show 

 the internal yolk-bag, b, almost entirely absorbed, and with a mere vestige 

 of the canal of communication remaining; d, the intestine; e, the stomach. 



Fig. 2. Back view of a foetal Torpedo, showing the accessory fasciculus of branchial 

 filaments, described at p. 537. 



Fig. 3. A. The glandular structure in the oviduct, just above the uterine cavity of 

 the T. diversicolor. 



Fig. 4. The uterine organs of the T. oculata, the infundibulum, ovaries, oviducts, 

 uterine cavities (one laid open), and their common aperture in the cloaca. 



Fig. 5. The bulbous vessels (supposed to be auxiliary hearts) connected with the 

 aorta. 



