of the Oil Beetle, Meloé, and of the Strepsiptera. 341 
very recently impregnated, or, at latest, on the day afterwards, when the male 
Stylops came forth, the eggs within her body were at least from sixteen to 
eighteen days before they gave birth to the larvae. Having the specimen of 
Andrena at the second day after the young Stylops began to make their ap- 
pearance, [ had full opportunity of observing them issue from their parent. 
Their number was truly astonishing. Mr. Smith calculated that from two to 
three hundred came from this single specimen, but this is very far short of 
the real number, which, for so small an object as the female Stylops, was in- 
credible. I am almost afraid to state, lest I should subject myself to doubt, 
that my own observations lead me to believe there were more than twice as 
many thousands ; since, in a small collection of some of these very specimens, 
which I preserve between plates of tale, there are nearly two hundred and fifty, 
yet these do not constitute one-tenth of those produced, and there are still 
more than three times as many of these larve attached to the preserved bee 
now exhibited* from Mr. Smith's cabinet. 
So extremely small are these little insects at their birth, as already shown 
in the account given of the ova, that, on measuring them on a micrometer- 
plate beneath a high power, I found that their average length did not exceed 
twenty-two thousandths, or about one forty-sixth of an inch,—one-twelfth 
of that of the male insect in the imago state. 
When we contemplate for an instant this diminutive Stylops clinging to a 
hair of the bee in which it has been bred (fig. 22), and then glance to the 
Mylodon of old,—the gigantic Sloth of a former world,—and remember that 
the same primary laws of organization have regulated the production of both, 
we are as much lost in wonder and astonishment at the comprehensiveness of 
thone laws, as when contemplating those which regulate the motions of the 
universe. The larva Stylops has its system of parts for motion, for the assi- 
"Sr beeper meer 
, ing the head and anal 
segments. It is hexapod, and is furnished with long caudal setze, 
The Aead, or first segment, is short, rounded anteriorly, and a little d 
pressed in the middle, and on its upper surface there is a lunated row of 
* The stylopized Andrena, together with specimens of the larvz, 
the reading of this paper, were exhibited to the Soci ety at 
2*2 
