96 Wisconsin Academy of Sciences , Arts and Letters. 
pigmented and were ready to escape from their envelopes. When the chorion 
was removed, the serosa and first cuticle were found covering the embryo,, 
the hypodermis of which had already secreted a second chitinous layer. 
The shrunken but still conspicuous pleuropodia were attached to the 
pleurae laterad and close to the insertion of the saltatorial leg. A 
dark brown granular substance was collected in large masses over the head 
of the embryo, in the spaces betweeen the legs and the envelopes and on 
the surface of the pleuropodia, both of which were easily torn from the 
body and left adhering to the serosa and first cuticle. To these membranes 
also adhered much of the granular dark brown secretion. When I at¬ 
tempted to stain embryos still in possession of their pleuropodia, I made 
the same observation as on Blatta embryos of the corresponding stage: 
the pleuropodia were colored but the chitinous covering of the remainder 
of the body prevented the stain from entering the subjacent tissues. Sec¬ 
tions through the first abdominal segment of embryos in this advanced 
stage [Figs. 13 and 14] show that the peduncle of each pleuropodium is 
much attenuated and inserted on the cuticle at the bottom of a rather deep 
pit in the pleural hypodermis [eccl.]. The appendage is therefore cut off 
from the living tissues of the body and, being very loosely attached, is 
easily shed by the embryo during the movements preparatory to hatching. 
A section through the broad portion of the organ in the present stage [Fig. 
14] when compared with a section of the organ in its prime [Fig. 12] shows 
the extent of dissolution. The cell boundaries, faint but still perceptible 
in Fig, 12, have now disappeared and the organ has become a syncytium. 
Those portions of the cytoplasm which border the central cavity [ cv .] are 
filled with numerous vacuoles of different sizes. The nuclei have lost their 
regular arrangement, and in many cases also their evenly oval contours; 
their cytoplasm stains more deeply and their chromation is aggregated to 
form larger masses. The granular secretion [s] surrounding the organ and 
filling such spaces as are left between the embryo and its envelopes stains 
deeply in haematoxylin and seems to be a later formation than the homo¬ 
geneous secretion indicated at as in Fig. 12, between the amnion and body 
of the younger embryo. The abundance of this granular substance cling¬ 
ing to the walls of the shrunken pleuropodia and heaped about the legs in 
the immediate vicinity would seem to indicate that it is to be regarded as 
a secretion of the pleuropodia or of one of the embryonic envelopes and 
not as the decomposed amniotic secretion. 
Cicada septemdecim. Fabr. 
(Plate 3, E’igs. 19 ancl 20.) 
Most entomologists are familiar with the small ova deposited by this 
noxious Homopteron in short parallel rows in the twigs of our native trees. 
The eggs are translucent, so that the stages of embryos killed in Carnoy’s 
fluid heated to 70° C., which renders the yolk transparent and the embryo 
