1917] “ilcox—Rearing Insects for Experimental Purposes 7 
EXPLANATION OF PLATE. 
Fig. 1. Syneytium of growing amcebocytes. 
Fig. 2. A type of mulberry corpuscle. 
Fig. 3. Amoeboid amcebocyte. 
Fig. 4. Round amoebocyte. 
Fig. 5. Minute amcebocyte. 
Fig. 6. Cytoplasmic free cell. 
Fig. 7. Degenerating amoebocyte with a few small, refractive 
crystals in cytoplasm. 
Fig. 8. Degenerating amcoeboycte with numerous large, refrac- 
tive crystals in cytoplasm. 
Fig. 9. Disintegrated amcebocyte showing liberated granules 
and crystals. 
Fig. 10. Double crystal formed by a normally disintegrating 
amecebocyte. 
NOTES ON REARING INSECTS FOR EXPERIMENTAL 
PURPOSES AND LIFE-HISTORY WORK! 
By ALE. Wircox: 
Gipsy Moth Assistant, U. 5. Bureau of Entomology. 
INTRODUCTION. 
During the past two years I have been rearing insects for experi- 
mental and life-history studies. While engaged in this work it 
became necessary to develop new rearing methods and to modify 
some of the old ones. 
The rearing of insects from egg to adult is not always an easy 
task. Unforeseen difficulties arise anew with every species, in 
consequence of which I am offering these notes with the hope that 
entomologists will find them serviceable. 
During the life history of insects reared artificially, the following 
must be observed: 
1 Contribution from the entomological laboratory of the Bussey Institution in codperation 
with the U.S. Bureau of Entomology. (Bussey Institution, No. 121.) 
2 The writer desires to express his thanks to those who rendered valuable assistance in the 
preparation of this paper: Prof. William M. Wheeler, Dean of the Bussey Institution, Harvard 
University, and Mr. A. F. Burgess, in charge of gipsy-moth work, for their helpful criticisms; 
Dr. R. W. Glaser and Dr. J. W. Chapman of the Bureau of Entomology, for their suggestions; 
and Mr. Harold A. Preston of the same Bureau for the preparation of the illustrations. 
