AMERICAN NATURALIST. 
FEBRUARY, 1889. 
A CONTRIBUTION TO THE KNOWLEDGE OF 
THE GENUS BRANCHIPUS. 
BY O. P. and W. V. HAY. 
I. T/ie Hatching of the Eggs of B. Vernalis Kept in Dried 
Mud. Branchipus vernalis is, according to our present knowledge, 
distributed from Eastern Massachusetts to Western Indiana. It 
lives in ponds which are filled with water during the colder parts 
of the year, but which are dry during the summer months. The 
eggs, therefore, which when laid by the females sink down into the 
mud, remain during the hot months enclosed in the dry and baked 
earth and resume their activity and complete their development 
only when the cold autumn and winter rains come on. 
The species of Branchipus whose life-history has been most thor- 
oughly studied is B. stagnalis of Europe. As long ago as 1820, 
Benedict Prevost experimented with its eggs. Some of these were 
kept in dried mud for six months and at the end of that time on 
being put in water developed into swimmmg larvee. Some of the 
eggs, similarly dried, were sent to M. J urine at Geneva, and this 
naturalist also succeeded in obtaining the young.» 
Naturalists have hitherto not been so successful in hatching out 
the eggs of our species. In Dr. A. S. Packard's •' IVIonograph of 
' Claus, Branchipus stagnalis, etc. Gottingen, 1873, p, r. 
