352 WHEELER. [Vor. III. 
that there are some salts of uric acid. That they are not of 
a fatty nature is indicated by the fact that treatment of the 
embryos with hot benzole, chloroform, or clove oil has not the 
slightest effect upon the bodies in question. Further examina- 
tion with a high magnifying power shows that they consist of 
small spheres of an extremely refractive substance, from the 
centre of which dark lines radiate in an irregular manner, pro- 
ducing the same appearance seen in the crystals of urea from 
the Malpighian vessels. It was this similarity which first sug- 
gested the true nature of these bodies; and further tests con- 
firmed this view, for, after heating an embryo with nitric acid 
upon a glass slide, and then adding a little ammonia, the char- 
acteristic red color of Murexid was formed. A still further test 
was formed by dissolving the granules in dilute caustic potash, 
and then precipitating the urea by adding acetic acid, although 
this method did not give such definite results as the first.” 
The embryonic development of A/atfa is completed by about 
the thirtieth day from oviposition. 
Figure 49 shows the embryo soon after hatching. Shortly 
after leaving its narrow place in the capsule, the insect under- 
goes a peculiar change in shape. While confined by the cho- 
rion the diameter from one pleural wall to the other is about 
one-third the dorsoventral diameter of the insect. Soon after 
hatching, its dorsoventral diameter is only about one-third as 
great as its greatest breadth. The tip of the abdomen, ventrally 
flexed in the egg, bends dorsally as indicated by the position 
of the anal stylets, which now point directly upwards and out- 
wards. The spines and onychia, most abundant on the legs, 
are developed shortly before hatching. 
Doryphora. 
Doryphora embryos, when carefully prepared, reveal much 
more in surface views than S/atfa embryos prepared according 
to the same methods. 
The last stage described is represented by Fig. 73. I shall 
pass over a few of the succeeding stages, and stop to describe 
the embryo represented in Fig. 72, which shows, with great 
clearness, all that has taken place in the omitted stages, and 
makes a description of them unnecessary. The figure is slightly 
