40 ON THE AGAMIC REPRODUCTION AND MORPHOLOGY OF APHIS 
tarsi, were blackish. The antennze were not more than equal to half 
the body in length; they were seven-jointed, the penultimate joint 
being somewhat swollen at its extremity. Both this and the pre- 
ceding and following joints were so sculptured as to appear, at first, 
minutely annulated. The basal joint was the thickest of all; the 
second less thick, but stronger than tne others. The proximal half 
of the antenne was sparsely setose. The promuscis was short, ex- 
tending, when deflexed, no further than the posterior edge of the 
prothoracic sternum. The abdomen tapered into a cone beyond its 
sixth somite, on whose dorso-lateral region the very short trumpet- 
mouthed siphons were situated. The abdomen was terminated by 
two subcylindrical rounded setose tubercles, of which the lower was 
the larger. They had the anus between them, and acted as anal 
valves. The posterior limbs, when fully extended, hardly reached 
beyond the end of the abdomen. 
The eggs when first laid are of a dark green hue and very soft ; 
afterwards they appear to become black. 
The vulva of the oviparous Afpfzs (B) opens between the eighth 
and ninth abdominal sterna, the eighth (8) being a little prolonged, 
so as to form a sort of inferior lip to the vaginal aperture (Pl. XL. 
[Plate 5] fig. 1). The vagina (C) is a thick-walled tube provided 
with a layer of external transverse, and internal longitudinal, striated 
muscles. After entering the sixth abdominal somite, it divides into two 
branches—the oviducts (DD), whose walls exhibit the same muscu- 
larity, but are less thick. Both vagina and oviducts are lined by a 
well-developed epithelium. 
The oviducts divide into four ovarian czeca, whose delicate struc- 
tureless wall is unprovided with muscles, and lined by a columnar 
epithelium. Each cecum is ordinarily divided by constrictions into 
six chambers. Of these I found the posterior (that nearest the 
vulva) (E) always empty, and of nearly the same length, though of 
a much smaller diameter than that which precedes it, or the fifth 
from the apex of the ovarium. This fifth chamber (F) always con- 
tained a fully formed ovum, provided with a chorion and an opaque 
coarsely granular yelk. 
The fourth chamber (G) is smaller than the fifth; it contains a 
coarsely granular vitelline mass in which no germinal vesicle can be 
perceived, and which ordinarily has no investing membrane. 
The third chamber (H) is still smaller; and its contents are 
usually only slightly granular, so that the germinal vesicle and spot 
of the ovum in this chamber are beautifully distinct (fig. 2). 
The second chamber (I) is the smallest of all; the germinal 
