Sometimes the eggs have a smooth surface, again they may be ridged or like hammered brass or silver.  The shells are very thin and break easily.  At one side a place can be detected where the fertilizing fluid enters.  The coming caterpillar begins to develop at once and emerges in from six to thirty days, with the exception of a few eggs placed in the fall that produce during the following spring.  The length of the egg period differs with species and somewhat with the same moths, according to suitable or unfavourable placing, and climatic conditions.  Do not accept the experience of any one if you have eggs you very much desire to be productive of the caterpillars of rare moths; after six days take a peep every day if you would be on the safe side.  With many species the shells are transparent, and for the last few days before emergence the growth of the little caterpillars can be watched through them.

When matured they break or eat a hole in their shells and emerge, seeming much too large for the space they occupied.  Family characteristics show at once.  Many of them immediately turn and eat their shells as if starving; others are more deliberate.  Some grace around for a time as if exercising and then return and eat their shells; others walk briskly away and do not dine on shell for the first meal.  Usually all of them rest close twenty-four hours before beginning on leaves.  Once they commence feeding in favourable conditions they eat enormously and grow so rapidly they soon become too large for their skins to hold them another instant; so they pause and stop eating for a day or two while new skin forms.  Then the old is discarded and eaten for a first meal, with the exception of the face covering.  At the same time the outer skin is cast the intestinal lining is thrown off, and practically a new caterpillar, often bearing different markings, begins to feed again.

These moults occur from four to six times in the development of the caterpillar; at each it emerges larger, brighter, often with other changes of colour, and eats more voraciously as it grows.  With me, in handling caterpillars about which I am anxious, their moulting time is critical.  I lost many until I learned to clean their boxes thoroughly the instant they stopped eating and leave them alone until they exhibited hunger signs again.  They eat greedily of the leaves preferred by each species, doing best when the foliage is washed and drops of water left for them to drink as they would find dew and rain out of doors.  Professor Thomson, of the chair of Natural History of the University of Aberdeen, makes this statement in his “Biology of the Seasons”, “Another feature in the life of caterpillars is their enormous appetite.  Some of them seem never to stop eating, and a species of Polyphemus is said to eat eighty-six thousand times its own weight in a day.”  I notice Doctor Thomson does not say that he knows this, but uses the convenient phrase, “it is