Cuap. II. FOLDINGS OF THE EMBRYONIC DISC. 573 
Soon after hatching, this Turtle discharged from its intestines a glutinous mat- 
ter with green blood discs, (Pl. 19, fig. 55,) more or less broken up, and also 
bodies which appear to be crystals of uric acid (fig. 35a, a, b, ¢, d, e). 
Each of the lungs (PI. 25, fig. 3a, /) occupies as yet a small space, close upon 
the back of the liver (7, 7) and of the heart. The surface of the lungs is quite 
dark with pigment cells. The cells (Pl. 19, fig. 31, a, b) of the liver are similar 
to those of the last phase. The cells (Pl. 19, fig. 29, 29a) of the gall cyst are 
broad, long, and columnar, each containing a single large mesoblast. The wall of 
the cyst consists of only a single layer of these cells, which, seen in the direction 
of their length, appear polygonal. The contents of the gall cyst (PI. 19, fig. 33, 34) 
are, in a great measure, minute, dark granules, with bodies that appear to be the 
different stages of growth of blood corpuscles) The Wolffian bodies and kidneys 
(Pl. 25, fig. 3a, g, fig. 7, 7a) are quite broad and short, with blunt ends; the 
former are about equal in size to the latter. The kidneys (fig. 7, 6, 7a, 5) are 
supplied with numerous bloodvessels. The generative organs (fig. 7, ) are much 
broader and shorter than when we first noticed them, and do not equal the length 
of the kidneys. The cells (Pl. 19, fig. 50) of the female generative organ, the 
ovary, (Pl. 25, fig. 7, »,) are moderately large and sharply polygonal, and each 
cell contains a large, granulated mesoblast. 
The bloodvessels of the omphalo-meseraic system occupy the whole yolk sac, 
in the form of close meshes, (Pl. 18, fig. 4,) encased in a thick, tenacious layer 
of albuminous substance, containing innumerable yolk cells of various sizes (fig. 
4a). These anastomozing vessels belong to the return currents, and have quite 
thick walls, (fig. 4a,) which form a striking contrast with the excessively thin 
walls of the efferent vessels (fig. 2) of the superficial portion of the vascular 
area. The superior retractor muscle of the head has afforded excellent material 
to show the serial arrangement of granular bodies in the formation of muscular 
fibrille (Pl. 19, fig. 27, 27a). The central cartilage cells (Pl. 22, fig. 5, 6, 6a, 
6b) of the clavicle are widely separated from each other, and, judging from the 
branching nature of their contents, have begun to form a deposit of lime. The 
lower jaw (Pl. 9e, fig. 11, lla) has a considerable amount of lime deposited in 
its peripheric parts, especially along its upper edge. Upon making an_ oblique 
section of its length, (through #—s fig. lla,) a row of small cavities (fig. 11, 4, 
fig. lla, 6) are seen proceeding from the upper side of the cavity (fig. 11, 4, 
lla, a) im which the maxillary nerve runs; and each little cavity is filled by 
a prolongation of the maxillary nerve. One would suppose that these cavities were 
the future sockets of teeth, did we not know that Turtles possess nothing of the 
kind. However, we cannot doubt that they are typical tendencies toward the 
development of dental organs of mastication. The suture of the branches of the 
