516 ROBERT W. HEGNER 
matinkérnchens nennen will, Nebenkerne, nehmen allméhlich an 
Grosse zu, wobei sie dann eine sehr deutliche Membran an ihrer Ober- 
flache erkennen lassen, zugleich nimmt*der Inhalt an festen, farbbaren 
Substanzen zu. Diese treten theils als kleine, rundliche Nucleolen, 
oder als feine, wenig sich fairbende Fadchen auf. 
Da nach und nach immer mehr soleche Nebenkerne entstehen, finden 
wir bei etwas weiter in der Entwicklung fortgeschrittenen Eiern in 
der Region der Eiréhre, wo bereits Eifaicher und Nahrzellenfacher 
deutlich abgegrenzt sind, die Oberfliche des Eikernes von einer ganzen 
Schicht soleher Nebenkerne von verschiedener Grosse bedeckt, die sich 
gegenseitig berithren. So bleiben die Verhaltnisse auch in noch etwas 
ilterne Eiern. (pp. 144-145). 
These Nebenkerne, according to Blochmann, after multiply- 
ing by self-division become scattered within the yolk where they 
degenerate, none being present in the ripe egg. 
Among the other investigators who have observed similar 
bodies in the oocytes of insects are the following: Will (’84) and 
Ayers (’84) observed them in Hemiptera and considered them 
follicular epithelial cells which contributed to the formation 
of the yolk. Stuhlmann (786) has described them in many 
insects, including Musca, Periplaneta, Locusta, Pieris, Aphro- 
phora, Sphinx, and certain Coleoptera and Hymenoptera. 
They were called ‘Reifungsballen’ by him and were thought to 
be similar to the polar bodies which at that time had not yet been 
observed in insects. The ‘Reifungsballen’ appear at different 
stages of the growth period in different species and also have 
different fates; some of them fuse to form a large ‘Dotterkern’ 
which lies near the posterior end of the egg and resembles what 
I called ‘Keimbahn-determinants,’ 4nd others become widely 
distributed and disappear in the yolk. The possible origin 
of the ‘Ballen’ from epithelial cells is suggested but not con- 
sidered probable. Korschelt (’89) from a study of them in 
Bombus, concludes, as did Will and Ayers, that they are derived 
from epithelial cells. 
In Blatta germanica and Leptinotarsa decemlineata, Wheeler 
(’89) has described as ‘maturation spheres’ a number of globular 
bodies which appear after the egg nucleus migrates to the pe- 
riphery and prepares for maturation. In Blatta several of these 
spheres may be present. In Leptinotarsa a number of oval 
