Dr. Wyman on the Surinam Toad. 371 
mens three branchial appendages were visible on each side of the 
ad. The general aspect of the embryo, as it lies extended on 
the surface of the yelk, reminds us of the larval condition of 
Salamanders and Tritons. The vitelline vessels communicated 
with the trank hy means of two afferrent vessels on each side of 
the head, and several efferrent ones on the sides of the trunk. 
In a later stage as exhibited in another series of embryos (fig. 
3), the external branchize had disappeared, the legs (a) now uni- 
ted with the trunk. were terminated by an expanded extremity, 
the rudiment of a foot; the ventral lamine: as represented by the 
dotted line extended farther down upon the yelk, but still this 
last was to a great extent uncovered ; the nostrils were visible as 
round terminal depressions, but it was not ascertained if they 
communicated with the mouth. A small branchial fissure was 
tected on each side of the neck, and within this, as was shown 
by slitting open the mouth and cesophagus, there existed on each 
side a series of fringed branchial arches. 
- The most extraordiuary feature however of this stage was the 
peculiar change going on in the yelk mass; the whole of the yelk 
sibstance was nioulded into a spiral coil, fig. 3, and invested with 
a thin tunic, and thus converted at once into a spiral intestinal 
canal, the coils of which extend from the sides of the trunk to 
the most prominent portion of the yelk, and there changing di- 
fection and occupying the axis of the coil the intestine passes 
back again towards the trunk. The whole yelk-mass is, therefore 
Moulded into a spiral intestine. 
In the most advanced stages which were examined (figs. 4 
-and 5) the ventral Jaminz had almost entirely included the intes- 
tinal canal as seen in fig. 5; the papille and rows of tubercles 
Upon the skin were developed, the intestine had increased in 
length, and the extremities had become elongated and were pro- 
Vided with well defined toes. The legs were folded against the 
Sides of the body, usually one towards the back and the other 
towards the abdomen, and the tail which had become proportion- 
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