752 General Notes. [November, 
Altogether it is a very interesting case of the development of 
additional limbs, and is probably of commoner occurrence than 
is generally supposed. Its origin is probably to be attributed to 
injury or shocks, the same as that of monsters in general, as has 
been shown by direct experiment on eggs, and as I have been led 
to believe from the numerous cases where additional tails or 
dency, where the organism is making an effort to return to some 
remote ancestral form, an explanation which will not answer, 
however, with respect to the lizard’s tail. The theory of the 
archipterygium may explain it—Fno. A. Ryder. 
Tue Cocoons or MicroGastTer.—In examining the Microgaster 
which infests the different species of Macrosila, I have noticed 
several points in the spinning of the cocoon which are different 
from what are described in the very interesting note in the 
August number of the NATURALIST. 
Never having studied those which are found upon the Philam- 
pelus, I do not know to what extent, if any, the parasites of the 
potato worm differ from them in structure. 
First, as the worm issues from the body of its host, it does not 
assume the erect positicn even for a moment, but remains flexed, 
with its head ready to begin spinning as soon as the last seg- 
ments of the body appear. There is, apparently, no envelope to 
the body, and the first active movements are those of the head as 
it fixes the preliminary stay threads previous to spinning in the 
regular loop form. This goes on precisely as described in the 
note referred to until the worm has finished one side, has turned 
upside down and is ready to complete the other half of its case. 
Then, instead of beginning to spin at the bottom, it quickly 
flexes its body, thus bringing its head back to the “toe of the 
slipper,” from which it spins downward till the back of its host is 
reached and it is entirely enclosed. : 
The spinning of the two sides of the cocoon, then, is practi- 
cally upon the same plan. In the first half the straightening of 
the bent body proceeds from below upwards, in the second, from 
above downwards. The position of the extremities is, of course, 
reversed in the two instances. The second position, though 
apparently a difficult one to assume, is nevertheless easily taken 
by the worm, no matter what may be its position upon the body 
of its host. The time required for completing this envelope 1S 
from thirty to forty-five minutes. In the further lining and com- 
~ pleting the cocoon the worm can be seen to turn about four 
_ times before the structure becomes opaque.— Wm. A. Buckhout. — 
- CETONIA INDA INJURING Corn.—This common and generally 
ess beetle is reported by Mr. C. B. Smith, of Granby, Mass- 
injurious to corn. He sends us a specimen which he says, 
