Page:Popular Science Monthly Volume 27.djvu/398

382 The study of the geographical distribution of moths has led us a long way back in the history of our own race, to that East whence art and science sprang. There is only one other fact to be briefly mentioned here, and that is the discovery by Louis Agassiz, who accomplished so much toward an understanding of our entire fauna, of a tropical colony of moths inhabiting the southern extremity of the Peninsula of Florida. I have examined the specimens brought thence, now in the Museum at Cambridge. Standing in the way of the south winds and the Gulf Stream, Florida receives constant accessions to its tropical colony of insects. Not a few of the Florida moths seem to have changed a little, and the probability is that here also we may have to do with descendants of a very ancient colonization. Our continent, in fact, has harbored many immigrants besides the Pilgrim Fathers, who are distinguished among these by their greater importance, and the results of their adventurous voyage.

The celebrated receipt of Mrs. Glass, which is of such general application and has served so many literary purposes, must be employed before we can place our specimens of moths in the cabinet. And, indeed, everything depends upon the catching of them, and their appearance after being caught. The scales and the little fine fringes which edge the wings are but delicately fastened to the membrane of the wing itself, and are lost with the lightest rubbing. Some species can never be captured on the wing in a really perfect condition. When the "bee-hawks" (Hemaris sp.) emerge from the chrysalis, there is a dusting of fine scales over the glassy portions of the wings, which is scattered by the first fluttering flight of the insect:

Again, several moths are ornamented with patches of looser and bright-colored scales which are readily lost, the specimens still appearing fresh after they have vanished. Thus the "dark-red under wing" (Catocala cara) has the fore-wings adorned with spots of a greenish hue when it leaves the pupa, but they are apt to fall and the wings then appear all of a dark-brown. Not knowing this, the fresh specimens have been described as a new variety, by an enterprising and unfortunately somewhat critical writer, under the name Carissima.

We have the choice of pursuing our entomological prey in each of its stages of growth—of eggs, caterpillar, chrysalis, or moth. If we gather them in either of the first three states, we have to nurse them until they are brought to the last, and, since in this way we can always obtain bright examples, it is much preferred by moth-fanciers. It is, indeed, the only way to obtain adequate information about these insects, and, as they are usually brought through them all with less difficulty than the other insects in captivity, the breeding of moths becomes an alluring and profitable pursuit.

Egg-hunting is the least remunerating way of procuring moths,