The eggs are laid in early summer almost immediately after pairing, and hatch in course of a few days, the larvae growing through the summer. The cocoons are hung to twigs of trees by a silken cord, and quite often a leaf is utilized as the outer covering within which the elongate oval cocoon is built. In any case the cocoon bears resemblance to a withered curled leaf hanging by its petiole. In this manner cocoons hang upon the trees through the winter. They are found most commonly on wild cherry, this being apparently the favorite food plant of the larva. They feed however on a large number of common trees and shrubs. [Illustration: FIG. 2. _Callosamia promethea_, male. (H. O. ad. nat. 1880.) ] The figures of the moth, male and female, were drawn twenty one years ago, and having now come of age they may perhaps be trusted to make their first public appearance. MEETING OF THE BIOLOGICAL CLUB. The Biological Club met in Zoological lecture room on the evening of April 1, 1901. Professor Osborn presided. Professor Schaffner reviewed a paper entitled _Zur Kenntniss der Zelltheilung bei Myriopoden_, published in _Archiv fur Mikroskopische Anatomie_. Dr. Morrey spoke on the subject, “Two years in Europe as a Student.” Most of the time was spent at the University of Vienna, although the University at Zurich and the Pasteur Institute at Paris were each attended for a short term. The University of Vienna ranks among the first in the advantages offered to medical students. The hospitals of the city are noteworthy on account of the large number of cases and the great variety of diseases treated. The numerous holidays observed in Vienna seriously interrupt college work. Hardly a week passes in which there is not one or more holidays on which work is wholly suspended. The speaker placed on the exhibition table a fine series of photographs procured during his stay abroad. These furnished a treat for those present after the regular program was completed. JAS. S. HINE, Secretary. NEWS AND NOTES. The Summer Field Meeting of the Ohio State Academy of Science will be held at Wooster, Ohio, on Friday and Saturday, May 31 and June 1, 1901, under the auspices of the University of Wooster, the Ohio Experiment Station and the Wooster Field Naturalist’s Club. The plan includes Friday about the small lakes southwest of Wooster, and an evening meeting in Wooster; Saturday morning at the Experiment Station, to be followed by an excursion to North Lawrence with its mines and Fox Lake with its tamarack bog. Prof. Charles S. Prosser in an article in the Am. Jour. of Sci. 11:191–199, 1901, discusses the names applied to the formations of the Ohio Coal measures. The following names are proposed.