PHAGOCYTOSIS IN THE POSTEMBRYONIC 
DEVELOPMENT OF THE DIPTERA. 
VERNON L. KELLOGG. 
IN the most recent considerable! paper on the postembry- 
onic development of an insect of complete metamorphosis, the 
author lays much stress on the small part which phagocytes 
play in the breaking down of the larval tissues during the 
metamorphosis of the insect studied — the little brown ant, 
Lasius flavus. In this respect the author sees in the meta- 
morphosis of Lasius (belonging to the Hymenoptera) a sharp con- 
trast to the metamorphosis of the Diptera, in the best-known 
example of which, the much-studied Calliphora, phagocytosis 
plays an all-important part. Korotneff? found in the case of 
the degeneration of the larval muscles of Tinea (Lepidoptera) 
that there was no phagocytosis. Rengel? in studying the 
changes in the alimentary epithelium of Tenebrio and other 
Coleoptera, found also no phagocytosis, and Needham,* in a 
careful study of the flag weevil (Mononychus vulpeculus), simi- 
larly found a complete lack of phagocytosis in the histolysis 
of the larval tissues of this insect. Karawaiew strongly agrees 
with Korotneff and Rengel in believing that phagocytosis is 
a phenomenon of postembryonic development associated with 
the length of time occupied by the metamorphosis. With the - 
blowfly the metamorphosis occupies but a few days; with 
Tinea, a little more than two weeks ; with Tenebrio, several 
weeks, according to the temperature; and with the ants still 
: Karawaiew, W. Die nachembryonale Entwicklung von Lasius flavus, Zeitschr. 
J. wiss. Zool, Bd. lxiv (1898), pp. 385-478, Pls. IX-XII, and 15 figs. in text. 
? Korotneff, A, Histolyse und Histogenese des Muskelgewebes bei der Meta- 
während der Metamorphose, Zeitschr. J. wiss. Zool., Bd. lxii (1896). 
* Needham, J. G. The Metamorphosis of the Flag Weevil (Mononychus 
Vulpeculus), Bio’. Bull., vol. i (1900), pp. 179-191. 
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