960 
Journal of Agricultural Research 
Vol. V, No. 21 
Technique. —For description, specimens were mounted in balsam in 
the usual way after having been dehydrated and cleared. Eggs were 
fixed with acetic-alcohol-sublimate solution, and after washing were pre¬ 
served in 70 per cent alcohol. Those which had been preserved for some 
months gave better results on sectioning than did newly fixed material. 
Clearing was done in cedar oil, and sections from 5 to 10^ in thickness 
were cut; those 8ju gave the best results. Staining was done with Dela- 
field's hematoxylin, orange G and picric acid, and Mayer's add hemalum. 
Borax carmine was used for staining in toto. 
THE EGG 
DESCRIPTION 
Size, 0.572 by 0.281 mm. Form oval, flattened on side next the bark; 
more or less covered with a glutinous substance which hardens with age. 
Color, glossy black. 
The newly laid egg is not, as has been frequently stated for this species, 
yellowish green in color. It is a decided light-yellow, with rarely a 
slight tinge of green. It does, however, become somewhat greener during 
the change from yellow to black. This change is completed in the shade 
(insectary conditions) in from one to four days, usually a little over one. 
The sterile egg can be easily separated from the fertile in that it is 
orange in color when laid. In one case such an egg finally turned to “ox 
blood,” but this was the only example out of more than a hundred in 
which any color change took place before the egg began to shrivel up, at 
which time it sometimes became orange brown. This shriveling usually 
took place in about a week or 10 days after deposition. 
LOCATION ON TREE 
The green apple aphis hibernates only in the egg stage. The eggs are 
laid in the fall on the smooth twigs, and especially on water sprouts. 
They are apparently never laid on the trunks of the trees, or even upon 
the branches. This is to be expected, since the females feed continuously 
during the oviposition period, and they would be unable to obtain their 
food through the thick bark (PI. EXXV, fig. 2). 
Unless the eggs are very abundant, they are usually deposited around 
and under the buds and in wounds in the bark. When abundant, however, 
they will be found scattered promiscuously over the twigs, and in some 
cases these will be entirely blackened with them. It is very interesting 
to note that in the winter of 1914 a careful survey of a large bearing 
orchard near Vienna, Va., revealed the presence of eggs only on trees in 
the south to west portion, and they were most abundant in the southwest 
comer of the orchard. These results were duplicated in an examination 
of a small orchard of 4-year-old trees on the laboratory grounds. More- 
