116 
Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
Copulation apparently produces an immediate change in the 
physiological condition of the female. Her behavior is modified— 
she no longer swims or rests near the surface of the water, but 
goes to the bottom and remains quiet; she also resists (at least for 
a time) the clasps of the males. 
All females carried on rhythmical movements within the ovi¬ 
sac. The organs within the chitinous covering rotated back and 
forth about the antero-posterior axis. Such movements were more 
rapid and pronounced in females carrying large eggs in the 
median portion of the ovisac. They doubtless help in the aeration 
of the eggs. 
SUMMARY. 
From the observations described it may be asserted that 
Bubranchipus dadayi shows certain adjustments to the conditions 
in which it lives. The coloration and behavior of the females are 
so correlated as to render them inconspicuous as they lurk among 
the dead leaves at the bottoms of ponds or wait for mates in the 
shadows of objects near the surface. The transparency of the 
males enables them to wander about with comparatively little 
danger of being seen; they are thus able to seek out and fertilize 
the females. As soon as a female has been provided with sperm 
she resists the advances of males, goes to the bottom of the pond 
in which she lives, and remains quiescent so that the eggs may 
descend into the ventral portion of her ovisac, undergo fertiliza¬ 
tion, and develop. 
BIBLIOGRAPHY. 
baird, w. — 1850. The Natural History of the British Entomostraca. 
Rlay Soc., London, viii & 364 pp., 36 pis. 
calman, w. t. —1911. The Life of Crustacea. New York, xvi & 289 pp. 
holmes, s. j. —1910. Description of a New Species of Eubranchipus 
from Wisconsin with Observations on its Reaction to Light. Trans. 
Wis. Acad. Sci., Arts & Letters, 16 (2), pp. 1252-1255, pi. 96. 
howland, r. b. —1911. Migration of Retinal Pigment in the Eyes of 
Branchipus gelidus. Jour. Exper. Zool., 2, pp. 143-158. 
mcginnis, m. o.—1911. The Reactions of Branchipus serratus to Lig-ht, 
Heat and Gravity. Jour. Exper. Zool., 10, pp. 227-239. 
Packard, a. s. — 1878. A Monograph of the Phyllopod Crustacea of 
