Vom Rath (’92) found _Gryllotalpa_ very poor material for following the spermatid changes. However, he described an oval body which he found varied in appearance, depending on the method of fixation. He calls it the “nebenkern” and thinks it goes to help form the tail. The description is too incomplete for comparison. Judging from _Gryllus_, I question its being very poor material. Bütschli (’71) studied the spermatid transformations in Acrididæ and Locustidæ along with that of other animals. He saw the object formerly described by St. George and named it “nebenkern.” He saw it divide into halves, elongate, and form the spermatozoon tail. The dividing of the nebenkern into halves seems to be an appearance quite common in insect spermatogenesis. I have myself seen it in several genera of Acrididæ—_Hippiscus_, _Arphia_, _Melanoplus_, and _Brachystola_; besides Bütschli, St. George, Henneguy, Platner, Paulmier and others have described it. Platner in his studies has given special attention to the nebenkern. In his first paper on “Pulmonates” (’85) he did not trace the origin of the nebenkern, but described it as consisting of four to six rods of different lengths and irregularly bent. These were connected, forming an irregular polygon. In its later stages he saw it with a mass of protoplasm pass down along the primary tail—an early protrusion of protoplasm. Finally it is lost. In his succeeding paper (’86, 1) he studied the “nebenkern” spindle remains—in the spermatogonia and spermatocytes of pulmonates. In the spermatids, as in the former generations of cells, the nebenkern grows out of the nucleus, where it, with the chromatin, had formed the spireme. It appears as a loop, which becomes larger, twisted, and entangled, and finally breaks loose from the nucleus. Later it goes to form the spiral covering of the primary tail, changing it to the axial filament and true tail. In his next paper (’86, 2) he describes the changes when the dividing of the protoplasm lags behind in the spermatocyte divisions. His description agrees in so many points with my own, that I shall quote his exact words: