to be met with, except on the bones and feathers from a particular species of raven. Among trees, the fir, the poplar, the oak and the birch, are peculiarly marked by the variety and abundance of these parasitic genera. They not unfrequently occur in the interior of the trunks of timber-trees. Mr. Schweinitz had in his collection, fine specimens of the Dematium aluta, taken out of the ships of war built by our government, on Lake Erie, where, in a few years, he remarks, "this little, fungulous enemy completely destroyed that fleet which had so signally vanquished the armament of Britain."
It was remarked by the cynic of old, when a pampered mouse had perched himself on a corner of his table, awaiting the eleemosynary crumb which the habit of intimacy between the two individuals had taught him to expect, that even Diogenes, too, had his parasites. If it be true, that all men, however humble, have their appropriate adherents—how much more so, when we descend to the inferior orders of creation? Scarcely, it is believed, can a species of animals, whether they inhabit air, earth, or ocean;—whether they proudly soar or lowly creep, be found, unattended by those which occupy, in regard to them, a parasitic character.
It will be remembered that in one of the papers of our late lamented Say, the parasitic insect, which feeds upon the Hessian fly is described. The study of cryptogamic botany makes known innumerable examples of the same general fact, in regard to that great department of nature's works.
In the synopsis of the "Fungi of Lusatia," the authors