246 Robert Wilhelm licgner. 



of the 1)0(', two kidney-shaped bodies lying on either side of the dorsal 

 vessel ; he considered these to be the female sexual organs. 



In several species of Hymenoptera Dohrn (1876) "fand in jungen 

 Larven die Anlagen der Ovarien als einen breiten birnformigen 

 Korper, dessen breite Flache in acht fingerformige Fortsiitze ans- 

 gezogen Avar, deren vier oben nnd vier darnnter liegen." 



Ayers (1883) studied Teleas, a parasite in the egg of Oecantlius 

 niveus. Here the germ-cells were budded off from the dorsal side 

 of a posterior enlargement of the nerve cord which curved upward 

 around the end of the mesenteron. A varying number of cells (two 

 to six) were thus produced embedded in homogeneous protoplasm. 

 ''They appear in sections of hardened specimens as though formed 

 endogenously within the substance of the still persisting mother 

 cells. . . These are shortly separated from the nervous cord, but 

 are connected to the blind end of the mesenteron by protoplasmic 

 filaments, usually one to each mother cell." 



The embryonic germ-glands of the bee were described by Grassi 

 (1884) as two solid strands, extending from the fourth to the eighth 

 abdominal segment. "Sono formazione mesodermica ; nascono press' 

 a poco ai confini tra il foglietto superficiale e il foglietto profondo 

 del mesoderma. . . ." 



The rudiments of the germ-glands were found by C^arriere (1890) 

 in Clialicodoma nivrwria at about the time when the first pair of 

 Malpighian tubules appeared. They lay near the dorsal wall of the 

 "Urhohle" in the fifth and sixth abdominal segments. 



Bugnion (1891) studied the postembryonic development of En- 

 cyrfiis fuscicoUis. The rudiments of the reproductive organs were 

 found in the middle of larval life; they were oval structures lying 

 on either side of the hind-intestine. During the second half of larval 

 life the sexes could be distinguished ; the testis remained small and 

 round, while the ovaries became oval and hirger. 



The "Anlage" of the germ-glands were found by Kulagin (1897) 

 in the parasitic Ilymenopteron, Platygaster lierrickii, lying near the 

 hind-intestine of an embryo in which the mesodermal somites were 

 forming. This rudiment was a paired structure composed of cells 

 similar to those of the mesentoderm, tlie only difference being their 



