1914] A Study of Dryophanta Erinacet. 
bo 
Or 
oenocytes of the honey-bee, speaking of them as permanent 
reservoirs which could not free themselves of their products, 
and had ceased activity. Berlese also describes oenocytes 
containing urates in many of the species he has studied. Perez, 
however, has pointed out that these workers have confounded 
urate cells with oenocytes, and it is significant to note that 
Berlese in his recent work ‘‘Gli Insetti’’ does not speak of 
oenocytes bearing urates, but limits that function to urate cells. 
The urate-bearing oenocytes that Rdossig describes in 
Andricus Malpighi have the distinct marks of urate cells, and 
are probably such. Further, he has shown that the injection 
of chemically pure urates into the plant tissue gives negative 
results, and therefore urates are not considered factors in gall 
production. Suppose that we concede to the oenocytes the 
function of secreting urates, have we gained anything? 
According to the above quotation, the urate-secreting 
function of the oenocytes is performed particularly during the 
molting and pupating periods when the Malpighian vessels are 
not functional. It has been shown that the oenocytes do not 
secrete urates. In all the species we have studied, urate 
crystals or urate globules have never appeared in the oenocytes. 
In Dryophanta erinacei we have never observed any unusual 
activity in these cells during the periods when the Malpighian 
vessels are not active, and the same can be stated of Holcaspis 
globulus, Dryophanta polita, Synergus erinacei, and the 
Eurytoma larva. Moreoever we do not know the chemical 
constitution of the secretion seen in the vacuoles of the oenocytes. 
Therefore we have no reason for assigning to the oenocytes the 
function of secreting urates. 
A Possible Correlation in the Development of the Malpighian 
Vessels and the Oenocytes. 
In discussing this phase of the problem, Rossig states that 
he cannot speak with certainty, but thinks that at least in 
Dryophanta divisa a correlation exists between the development 
of the Malpighian vessels and the oenocytes. He presents the 
following tabulation: 
MALPIGHIAN VESSELS OENOCYTES 
LENGTH CELLS NUCLEUS CELLS NUCLEUS 
D. divisa 460u. 50u. 36u. 50. 25 . 
ee My 600u. 73y. 50pu. 100. 50 J 
i Me 714y. 11dpu. 56u. 150z. 59. 
