of the Oil Beetle, Meloe, 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, I 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 talc, 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 larvee 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 

 those 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- 

 milation of food, and for the aeration of its fluids, like the most perfect ani- 

 mals. Its body is formed of fourteen segments, including the head and anal 

 segments. It is hexapod, and is furnished with long caudal setae. 



The head, or first segment, is short, rounded anteriorly, and a little de- 

 pressed in the middle, and on its upper surface there is a lunated row of 



* The stylopized Andrena, together with specimens of the larvae, were exhibited to the Society at 

 the reading of this paper, 



2 v2 



