Describes his brother Alexander's discovery of male of Bonellia, a striking example of dimorphism. Encloses a plate with notes on his brother's work.
The difficulty his wife, Sofya Kovalevsky, has had as a woman in being admitted to Berlin University. Kirchow [Gustav Robert Kirchhoff], at Heidelberg, has taken an interest in her.
1. Grown up female of Bonelia always sticking with her pyriform and in an aperture of a rock (Lacase— Ann. des Sc. Nat. vol X.)
2. Bonelia cut from the dorsal side g. ova in the Leibeshöhle, q. anal aperture; m. uterus; p. inpundibulum trough which the ova pass from the F cavity of the thorax into the uterus v bag where the planarias live
3. Supposed male magnified 70 diam; rs receptaculum seminis t. infundibulum; h. granular mass clothing the cavity, from which undeveloped spermatozoa are cast of; s. glomercili of spermatozoans swimming freely in the cavity
4. Infundibulum of the receptae. sem. (magnified 500 diam). with flimmerzellen