of the Oil Beetle, Meloé, and of the Strepsiptera. 337 
dinal suture. Behind these is a free crescentic margin (c), the boundary of 
the united pro- and meso-thorax. This margin conceals the vaginal outlet of 
the oviduct, which is in the fold between the head and thorax, as stated by 
Siebold. Its situation is very analogous to that of the outlet of the female 
reproductive organs in the Judide and other vermiform Myriapoda, in which 
the vulva of the female is in the mesothorax. i 
I regret that I was unable, through want of specimens, to make so precise 
an examination as I could have wished of the abdominal viscera of this insect. 
The abdomen (B) was soft, and divided into eight segments, and so large in 
comparison with the cephalo-thorax as to resemble greatly that of the pregnant 
female Termites. I had ruptured it while opening the body of the bee, so that 
I was unable to determine its precise form ; but noticed however that it was 
well-supplied with tracheal vessels, the chief of which at the sides near the 
base, and apparently connected with a large spiracle, as shown by Siebold, 
were of large dimensions, thus indicating a great extent of respiration. Like 
the body of the Termites, it seemed to constitute one immense ovary, crowded 
with thousands of ova of all sizes, in various stages of development, from the 
immature egg to the egg with the embryo almost ready to burst its envelopes. 
Tur Ece AND Empryo or Sryrops. 
The smallest ova which presented signs of having been fecundated and the 
development of the embryo commenced (fig. 23), were of a spherical form, and 
filled with a dark, yellow-coloured yelk, composed of masses of large nucle- 
ated cells (a). The yelk was surrounded by a transparent, colourless blasto- 
derma (5), and on one side (c) was impressed with a transverse sulcus. When 
measured on a micrometer-plate these ova did not exceed each at most one 
five-hundredth of an inch in diameter. Multitudes of others, which had not 
acquired their full size (fig. 24), measured only one thousand five-hundredth, 
or one two-thousandth of an inch. Those in which the changes had advanced 
sufficiently far as to indicate, by the doubling of the blastodermic layer on 
itself (fig. 25, d), a shadowing out of the form of the future embryo, measured 
about one three-hundred-and-fiftieth of an inch. Others, a little further ad- 
vanced, in which the outline of the embryo was more distinetly indicated 
(fig. 26), organization having been carried to that stage in which the greater 
