78 
Psyche 
[April 
3. At birth, the nymph is covered with a membraneous 
envelope which usually ruptures when the former is partially 
extruded through the vaginal slit. The nature of this envelope 
is still in question. I infer from my own observations on Macro- 
siphurn tenaceti that the membrane arises from the egg-follicle, 
which apparently does not degenerate. 
4. The nymph begins to feed in about fifteen to twenty 
minutes after birth. 
5. The position of the mother during parturition is the 
same as in feeding. Parturition apparently does not interfere 
with the latter process. 
LITERATURE CITED. 
BAKER, A. C. 1915. The woolly apple aphis. U. S. Dept. 
Agric. Rept. No. 101 : 1-56. PI. I-XV. 3 text-fig. 
BOUVIER, E.-L. 1919. La vie psychique des insectes. iv 
30 pp. Paris: Ernest Flammarion. 
BUESGEN, M. 1891. Der Honigtau. iv 90 pp. PI. I and 
II. Jena: Gustav Fischer. 
GLASER, R. W. 1917. Anthocyanin in Pterocovima smithice 
Mon. Psyche 24 : 30. 
JANET, C. 1909. Sur l’ontogenese de l’insecte. 1-130. Li- 
moges: Ducourtieux et Gout. 
MACCHIATI, L. 1883. La clorophilla negli afidi. Bull. Soc. 
Entom. Ital. 15 : 163. 
PRZIBRAM, H. 1906. Aufzucht, Farbenwechsel und Regene- 
ration einer agyptischen Gottesanbeterin ( Sphodromantis 
bioculata). Ztschr. Entw.-Mech. 22 : 149. 
1909. Aufzucht, Farbenwechsel und Re- 
generation der Mantiden. Archiv f. Entw.-Mech. 28:561. 
WEBSTER, F. M., and W. J. PHILLIPS. 1912. The spring 
grain-aphis, or “green bug.” U. S. Dept. Agric., Bu. 
Entom., Bull. No. 110 : 1-153. PI. I-IX. 48 text-fig. 
ZWEIGELT, F. 1915. Beitrage zur Kenntnis des Saugpha- 
nomens der Blattlause und der Reaktionen der Pflanzen- 
zellen. Centralbl. f. Bakt., 2. Abth., 42 : 265-334. PI. I-II. 
1 text-fig. 
