66 Remarks on Art. X. Vol. 1X. p. 288. 
cause which did not affect the others in so great a degree. 
It should be remarked that the insects emerged in a few 
weeks after their eating began to be heard, and that none of 
them eat more than three inches in length. I have just ex- 
amined the table of Mr. Putnam again, and can discover no 
appearance of the insects having eat intothe wood. An ex- 
amination for the same object was made by Mr. P. at the 
time the insects appeared. The form of the insect, so far 
as I recollect, was similar to that of which a figure is given by 
Mr. F. ; it was doubtless a species of Urocerus. 
Now, although a part of the passage may have been eaten 
by the insect before it became a chrysalis, and some acci- 
dental cause may have retarded the appearance of the last 
insect beyond the usual period peculiar to the species; 
which cause may have affected the egg, or the larva, or the 
chrysalis; there can be no doubt that the egg was originally 
deposited in the wood of the tree. Many insectsare furnish- 
ed with efficient instruments for piercing the substances in 
which they are led by an over-ruling hand under the opera- 
tion of instinct to deposit their eggs. The cause which ope- 
rated to retard the changes of the last insect, may also have 
prevented the developement of the others long beyond the 
usual time. In the case of these insects we have no proof 
that any part of the passage was formed by the larva. A 
particular knowledge of the insect is necessary to determine 
the point. The larve of insects, though often most vora- 
cious, are not always so; as we know in the case of the In- 
cust, grasshopper, and others. 
