4. The acrosome occupies a position in the angle between the nebenkern and the nucleus. It shows a central clear space surrounded by a darker mass which stains more intensely on one side. Later it passes to the front of the nucleus and forms the point of the spermatozoon head.
5. The mature spermatozoon consists of a sharp point, a slender, tube-like head filled with a clear fluid, and a long, thread-like tail.
Laboratory of Zoology and Histology,
University of Kansas.
September 27, 1901.
Bibliography.
1. Blackman, M. W., ’01: Spermatogenesis of the Myriapods. Kans. Univ. Quart., vol. 10.
2. Bütschli, O., ’71, 1: Vorläufige Mittheilung über Bau und Entwickelung, der Inseckten und Crustaceen. Zeitschr. f. wiss. Zool., Bd. 21.
3. —— ’71, 2: Nähere Mittheilung über die Entwickelung und den Bau der Samenfäden der Inseckten. Zeitschr. f. wiss. Zool., Bd. 21.
4. Calkins, G. N., ’95: The Spermatogenesis of Lumbricus. Journ. of Morph., vol. 11.