state agricultural society. 
785 
OAK. TRUNK. 
has also given an account of it in his Treatise, p. 31G, under the name 
Xyleutes Robinice. This renders a few words of explanation necessary, 
to unscientific readers, particularly since in one or two instances hereto¬ 
fore I have followed Dr. Harris in sanctioning names which on more 
mature reflection I regard as invalid. 
It is now a well established rule or law with men of science, that a 
specific name when once validly imposed upon any plant or animal can 
never afterwards be changed. This rule, however, was disregarded by 
Fabricius when he formed a separate genus to include the Goat-moth and 
other similar insects, as he took the name Cossus which Linnaeus had given 
to that moth as the name for this new genus and gave another name to 
this species ; thus in effect robbing Linnaeus of the honor of having named 
and described this insect. Hubner, therefore, proposed the name Xyleutes 
for this genus, in order that the name Cossus might be restored to its typi¬ 
cal species. Hut, on the other hand, it is to be observed that the law 
alluded to had no existence in Fabricius’ day; the very course which he 
pursued was at that period the established rule, sanctioned by the example 
of his illustrious preceptor—Linnaeus himself having in repeated instances 
selected his previous specific names as the names of genera of which those 
species were the types, hereupon giving new names to the species. Thus 
our common Lumpyris ( Photinus ) corrusca, Linn., was originally the Lan- 
tharis Lampyris, Linn. Fabricius, therefore, so far from violating, con¬ 
formed strictly to the received rules of his day in this matter. And to 
condemn him now, upon an ex post facto law, will be grossly unjust. 
Moreover, to cancel the several generic names which are in the same cate¬ 
gory with the one before us, and which have been universally current in 
our books for nearly a century past, will be too great an innovation to be 
tolerated, except the propriety and justice of such a step were perfectly 
clear. AVe hence regard the name Cossus as the legitimate designation of 
the genus to which the insect before us pertains. 
Dr. Boisduval has recently described this moth as anew species, (Annales 
Soc. Ent., 2d series, vol. x, p. 323,) though under the same name, Cossus 
Robinice, he having doubtless found it thus ticketed in some of the Paris 
collections and being unaware that it had been previously described. 
Prof. Peek states that he had repeatedly seen this same locust worm 
and its burrows in the wood of the black oak. Dr. Harris more cautiously 
says a larva which cannot be distinguished from this, occurs in the red oak. 
Having bred several of these moths from larvae in the white oak, I 
have ascertained them to be identical with the species described as infest¬ 
ing the locust. Aud my observations lead me to the belief that, in the 
State of New-York at least, these insects are bred in the oaks to a much 
greater extent than in the locust, for I have never seen an instance of their 
large perforations in the wood of the locust, whilst in the oaks they have 
been noticed repeatedly, and for many years before I lcuew what insect was 
t e culprit that occasioned this serious michicf. I therefore enter it under 
[Ag. Trans.] 50 
