of the Oil Beetle, Meloé, and of the Strepsiptera. 339 | 
closes the embryo is tensely stretched, the segments of the thorax of the 
future larva, as well as those of the abdomen, are distinctly marked, and 
traces of an alimentary canal are easily distinguished, although the whole 
interior of the body is still composed of cells. In the last stage of the em- 
bryo (fig. 32), immediately before rupturing its envelopes, the ovum measures 
about one-eightieth of an inch in its long diameter. The embryo is now 
completely formed. The whole of its abdominal segments, as well as its 
thoracic, have their armature of marginal spines. The minute head of the 
embryo, flattened, acute and wedge-shaped, projects forwards from the pro- 
thorax, and pressing against one portion of the envelopes whilst the caudal 
extremity is forced, by the growth of the body itself, in an opposite direction, 
the ovum is made to assume an irregular ellipsoid form, and by a continua- 
tion of the forces of growth the membranes and shell are at length burst, and 
the young Stylops comes forth in the oviduct of its parent as an active hexa- 
pod. ‘The whole of these changes take place in the ovum within the body of 
the female Stylops, herself contained within that of the bee. 
I regret that I was unable to obtain other specimens of Stylops for dissec- 
tion at the period when the larve have burst their envelopes. Enough how- 
ever is shown in these observations to prove, with Dr. Siebold, that the female 
Stylops is viviparous; and also, that the eggs do not all become matured at 
precisely the same period, but that there is a range of some days between the 
hatching of the earliest and of those which appear last. That this is the fact, 
was proved to my satisfaction in observations made on another stylopized 
specimen of Andrena. 
On the 27th of May, only a few days after receiving the Specimen which 
contained these embryos, Mr. Smith favoured me with the loan of a stylopized 
Andrena Trimmerana, which he had also captured at Hampstead about the 
dier 10th of that month, and which had been in his possession alive during 
b. odd sixteen or eighteen days. The bee died on the 258 of May, and 
y one or two specimens of Stylops larvze made their appearance. 
On the following day many more came forth ; and soon after the bee was placed 
Sones tet thay comleily reed ns rn nf ie Spo ach 
, J pletely covered the whole of the posterior part of the 
abdomen of the bee, both on the upper and under surfaces, like dust which 
VOL. Xx. y , 
