All the eggs used in the following investigation were collected from a small pond in the eastern edge of the city of Indianola. The eggs were gathered from time to time at intervals of from one to three days, between June 20th and September 30th, 1902. They were found in abundance along the bank, in water from one to six inches deep. Usually they were attached to a piece of wood, or some plant growing in the edge of the water. Many were also found attached to the bottom. A few were found floating in the water, but as by far the greater number were attached, it is probable that those found floating had broken from their attachment, or by some accident had not been fastened.
Proceedings of the Iowa Academy of Science
©1909 Iowa Academy of Science, Inc.
Craven, W. N.
"Some Observations on the Embryology of Chronomus,"
Proceedings of the Iowa Academy of Science, 16(1), 221-228.
Available at: https://scholarworks.uni.edu/pias/vol16/iss1/29