; 
1881. ] The Brain of the Embryo and Young Locust. 373 
bodies are present, though an early larval stage shows, in place 
of the calices, four symmetrically situated balls of much smaller 
size; the central body was very flat, and the other parts were 
wanting. In the pupa all the parts had attained their definite 
shape. It appears from his observations that the calices are the 
last to be developed. 
He then gives the results of his examination of the brain of 
caterpillars, as compared with that of the adult sphinx moth. In 
a caterpillar examined near the time of pupation, the central body 
is very much undeveloped, forming a small linear transverse body 
(Querleiste), while the different parts of the mushroom body are 
indicated. In smaller caterpillars it is scarcely possible to work 
out the development of the brain. In that of Pontia brassice the 
mushroom body and central body were undeveloped, while in 
that of an Euprepia larva the double stalk of the mushroom body 
was developed, as well as roundish calyx masses. But in a Noc- 
tuid larva the entire mushroom body, including well-developed 
trabecule and a very flat central body, was present. 
The brain of the mature pupz of Lepidoptera, for example 
Saturnia carpini, contains all the portions of the adult brain, and 
in the same relative proportions. Buta brain of Sphinx ligustri, 
in a considerably younger stage of development, did not differ 
much from the brain of the larva. 
We offer the following observations on the brain of the embryo 
locust, shortly before hatching, with much diffidence, as we are 
liable to be corrected by future observations in the same direc- 
tions. The embryos were taken from the egg-shell, hardened in 
the usual manner, and then cut by Mr. Mason, the sections being 
frontal, the entire insect being embedded in a mixture of paraffine, 
wax and oil. 
In the youngest stage (which we will call stage A) observed, 
the body and appendages were formed and the eyes with their 
facets, the pigment mass coloring the cornea pale reddish. 
At this stage, as seen in section 7, the antennal and optic lobes 
of the brain are indicated, but the central body and mushroom 
bodies are not yet differentiated. Ina plane lying in front of the 
optic and antennal lobes, the brain is divided in each hemisphere 
into two regions or lobes, 2. ¢,, an upper and lower cerebral lobe. 
From these embryonic cerebral lobes, are eventually developed 
* Compare the 2d Report of the U. S. Entomological Commission, Pls, XII,-XtUt. 
