i 
560 EMBRYOLOGY OF THE TURTLE. Part III. 
an anus. The mesenterium, (Pl. 9e, fig. 8, x°, fig. 8, a) that part of the 
intestino-subsidiary layer which keeps the intestine suspended from the median 
line of the body, may now be recognized as the pendent curtain which was 
formed by the subsidiary layer in a much younger embryo (see p. 552). That 
part of the. intestine which passes along above and around the liver (Pl. 9e, fig. 
8, r; Pl. 18a, fig. 9, 7) has become considerably swollen, (Pl. 9e, fig. 8, 7’; Pl. 
18a, fig. 9, 7°,) so as almost to equal the proportions of the full-grown stomach. 
The respiratory apparatus (Pl. 24, fig. 2, 7, @, fig. 2a) has separated entirely from 
the intestine, (fig. 2, 7°, n‘,) and the lungs have become swollen (fig. 2, 7, fig. 
2a): The liver .(PL.9e,; fig. 85.7 5: Pi» 18a, figs 8; oye fied) 957), 180 very. danke 
and has lost the globular form of earlier periods, (p. 556, Pl. 24, fig. 9a, 7,) and 
become more flattened vertically, and lobed on the left side, where it overlaps 
the stomach (PI. 18a, fig. 9, 1”). 
The Wolffian bodies (Pl. 9e, fig. 8, 9, fig. 8a, g'; Pl. 18a, fig. 7, g, fig. 7a, 
q, fig. 8, 9, fig. 9, g) occupy fully one half the length of the body, and exhibit 
very clearly the zigzag striae spoken of in a former page (p. 557). In a trans- 
verse section of the embryo (Pl. Ye, fig. 8) just behind the fore feet, the duct 
(g') of the Wolffian body (g) is shown to be a dorsal channel, and already of 
a considerable diameter. 
The “allantois «((PL, 14, fig. 2; 2a, 8 )poRly 18, fig. 8% Pl W8a, sig. Wai 
fiz. 8, 7°, fig. 9, 7, y®) reaches from the head to far beyond the tail, and laps 
over upon the right side of the body, so as to cover a large part of the pos 
terior region of the body (Pl 14, fig. 2a). In the case of another embryo, (PI. 
14, fig. 2,) of the same degree of development in other respects, the allantois 
overlaps all but the head and shoulders, and extends so far beyond as to cover 
four fifths of the area pellucida. The bloodvessels of this organ are very large 
and thick, and anastomoze with each other by innumerable capillaries. It is a 
remarkable peculiarity of the allantois that its arteries (Pl. 18a, fig. 8, 7°, fig. 9, 
jy’) and veins (PI. 18a, fig. 8, 7, fig. 9, 2?) run parallel and close to one another 
for a long distance, in that part of the organ which is outside of the body. In 
a view from below, (Pl. 18a, fig. 7a, and 9,) it is shown how the allantoidian arte- 
ries (j°) arise, one from each side of the dorsal artery, (j*,) and, bending around 
the intestine, (z',) converge just below it, and thence run along the narrow pedun- 
cle of the allantois out into its great expanded mass. 
The abdominal opening is contracted so as to equal about one sixth of the 
length of the body, exclusive of the tail. 
The feet project considerably beyond the body, and have an oval, paddle shape ; 
but, as yet, there are no signs of toes. This is the earliest period in which blood- 
vessels have been seen in the feet (PI. 14, fig. 2a), 




