502 ROBERT W. HEGNER 
stages these lie mostly near the nucleus (figs. 7-8), but later 
(fig. 9) become scattered throughout the cytoplasm. These 
granules stain best in iron hematoxylin after fixation in Meves’ 
modi‘ cation of Flemming’s solution. No evidence was obtained 
that they are of nuclear origin, although their early position near 
the nucleus indicates that they may have arisen in this way; or 
if not directly from the nucleus, at least through its influence. 
On the other hand, their sudden appearance within the cytoplasm 
indicates that they are cytoplasmic bodies which have resulted 
either from the aggregation of smaller pre-existing bodies of a 
similar nature or from the synthesis of other substances under the 
stimulus of the metabolic processes set up at the inauguration 
of the growth period. Duesburg (08) has recognized granules 
in the peripheral layer of cytoplasm in the full grown egg of the 
bee, especially near the nucleus in the thickened area which 
Petrunkewitsch (’01) has called the ‘Richtungsplasma,’ and 
considers them to be mitochondrial in nature. It seems probable 
that the bodies we have observed are the ‘mitochondria’ of 
Duesberg at an earlier stage. Paulcke (’01) failed to observe 
them. 
Discussion. The differentiation of the cellular elements in 
the ovaries of insects and the relations of the oocytes to the 
nurse cells has interested students of histology and cytology 
for three quarters of a century. Mayer, as early as 1849, ex- 
pressed the opinion that the nurse cells are abortive eggs. The 
connections between them and the oocytes were observed by 
Huxley (’58) in oviparous aphids, and were considered by him a 
nutritive canal for the conduction of food material from the nurse 
cells to the growing ege—a conclusion concurred in by Lubbock 
(60) and Claus (’64). Balbiani (’70), however, proved this 
‘nutritive canal’ to be a protoplasmic strand, but, as Wielowiejski 
(85) has pointed out, he was in error when he stated that the 
terminal chambers of the ovarioles of aphids contain a large 
central cell which gives rise to both the oocytes and nurse cells 
(abortive eggs). He nevertheless established the fact of a pro-_ 
toplasmic cellular bridge between these two kinds of cells. 
