Page:The Zoologist, 4th series, vol 5 (1901).djvu/222

198 opening the incubator a couple of weeks after the insertion of some well developed eggs "curious squeaking sounds were heard coming from the inside of the eggs, the sounds which in nature tell the mother that her young are about ready to hatch, and should be helped out of the mass of earth and leaves in which they are buried. These sounds are audible at a distance of fifteen yards or more, so that even when the eggs are buried in the nest the parent is probably able to hear the call of her young. The next day after the first sound was heard, one of the Alligators broke out of its shell, and a couple of days later two more hatched.

have received a Report on the Sarawak Museum, written by Mr. R. Shelford, the Curator, dated February, 1901. Apart from the details of the very satisfactory progress in the growth of this happily situated institution, the most interesting biological information relates to the seasonal variation in the Rhopalocera. Mr. Shelford writes:—

"It is noteworthy that Bornean butterflies do not, to any great extent, exhibit seasonal variation; such species that do are quite irregular in their appearance, e.g. the collection contains a long series of the so-called wet- and dry-season forms of Melanitis ismene (Cr.) which have been caught at all months of the year, and many examples of both forms have been caught in the same month. Neopithecops gaura (Butl.) is equally erratic in variability. It appears probable that the markings and colouration of the images of these variable forms are dependent on the degree of damp or dryness to which the young stages (egg, larva, or pupa) are subjected; if this is indeed the case, a spell of wet weather in the fine monsoon—a by no means unusual event—would produce a crop of wet-season forms, and conversely a spell of fine weather in the wet monsoon a crop of dry-season forms."

who has recently been appointed "Entomologist" to the Indian Museum, Calcutta, has recently published a most valuable paper on "The Food-Plants of the Butterflies of the Kanara District of the Bombay Presidency" (Journ. Asiat. Soc. Bengal, vol. Ixix. pp. 187-278). Apart from food-plants, the larvæ of many butterflies will, when they cannot obtain vegetable food, eat each other, or soft newly-formed pupæ. The Lycænidæ appear to have the distinction in cannibalistic propensities. One larva of Tajura cippus has been known to eat up over a dozen young ones of its own species. The tendency to cannibalism is not confined to the Lycænidæ, but exists also among the Pierinæ; the larvæ of Appias will eat each other, and any other species of larvæ feeding on the same food-plant as themselves, if forced to it by hunger.