24 Annals Entomological Society of America [Vol. VII, 
3. The oenocytes of the second larval stage are as large as 
those of the fourth stage. 
4. Among the inhabitants of the gall the largest oenocytes, 
(Figs. 83 and 84, Pl. X). were found in a Chalcid pupa, of the 
genus Eurytoma, while in a larva 144mm. long of the same 
genus the oenocytes were larger than those of a similar sized 
larva of Dryophanta erinacei. Figs. 85 and 86, Pl. X, show 
such an oenocyte. It is important to note that these occur in 
a parasite, which, as pointed out earlier in this paper, does not 
produce a gall. 
5. A 134mm. larva of Synergus erinacei possesses oenocytes, 
(Fig. 87, Pl. X), larger than those of a similar sized larva of 
Dryophanta erinacei, yet Synergus erinacei is only an inquiline. 
6. In an internal parasite of Dryophanta erinacei measur- 
ing 750u. the oenocytes are as large as those of a similar sized 
host. The parasite does not emerge from Dryophanta erinacei 
until after the gall has attained full growth, and hence has no 
part in the production of the gall. 
7. The Tenthredinid, Nematus pomum, which develops in 
a gall not produced by any product poured forth by the Mal- 
pighian vessels possesses oenocytes of considerable size, while 
the Malpighian vessels are normal, (Figs. 80 and 81, Pl. X). 
8. The same is true of Trypeta solidaginis, an oenocyte of 
which is shown in Fig. 82, Pl. X. 
Now since the largest oenocytes are not found in Dryophanta 
erinacei, but in a Chalcid parasite which is not a gall-maker, 
since there in no triple increase in the oenocytes of Dryophanta 
erinacei, and further, since there is a distinct limit within the 
range of which the varying oenocytes of all species really fall, it 
is clear that the conclusion of Réssig is not substantiated by the 
present investigation. 
“The general opinion that they are excretory organs des- 
tined to store up urates, especially, as shown by Verson in 
Bombyx, during the time when the Malpighian vessels do not 
carry out their function, during molting and pupation.”’ 
In general, students of oenocytes have considered them 
secreting organs, but as Perez has pointed out in “‘ Contributions 
a l’ Etude de Metamorphosis’? we do not know what their 
secretion 1s. 
It is true that Verson considered the cells secretors of 
urates in Bombyx, and Koschevnikov discusses the urate-laden 
