THE YOUNG NATURALIST. 



8 



takes most of the species, and we are already indebted to his quickness in 

 knowing what to observe, a most important matter in points like this. 



It has always been a subject of wonder to us that these fragile-looking 

 delicate creatures should brave the winter storms as they do. That larvse, 

 so small as to escape observation even from hungry birds, should survive the 

 snows and floods ; and, tiny little minims as they are, bear for weeks or 

 months, entirely without food, exposure that would break down the constitu- 

 tion of the strongest man. But cold in its due season seems as necessary to 

 their well-being as warmth and comfortable clothing is to ourselves. Snow, 

 covering the surface of the ground, buries beneath it all low-feeding species, 

 and effectually protects them from birds and other enemies. It has been 

 said that certain species are more abundant after a few snowy winters, and it 

 is quite likely to be the case. Insects in the perfect state are readily dis- 

 turbed by seasonal change. The Brimstone butterfly has often been noticed 

 on the wing in February, and we frequently have had the Tortoise Shell 

 brought' to us about the same time of year. If larvse are aroused prematurely 

 from their winter sleep, they will find no food ready for them, and must go 

 back to their torpidity or die. Pupae exist under different conditions, and 

 no change is possible with them but one. With certain species, with most 

 of species, we know that an increased temperature will hasten emergence, but 

 no time is gained thereby. If the emergence of a June insect be hastened 

 by increased temperature, and it appears in May, it only affords a longer 

 time for the species to remain in pupa next winter, The eggs may be de- 

 posited earlier, and the larvse feed up before its usual time, but the next brood 

 is not brought to maturity any earlier. In some species the entire brood emer- 

 ges every year, in others only part emerges the first year, some remaining to 

 a second season, some to a third or even more. The Small Eggar (EriogaUer 

 lanestris) is such a species, and specimens have been known to emerge every 

 year for several years in succession, from pupa reared from a single brood. The 

 advantage of this to an insect emerging in winter is very patent, and the 

 entire race might be lost in some severe winter but for this fact. But it is 

 not so well known whether this obtains with others of the winter moths, and 

 the causes of so curious a circumstance are not known at all. We have so 

 little data to go upon, as few observations have been made on this subject 

 as on the other, and though they may have a very close connection with each 

 other, we are quite unable to form an opinion on either. Will our readers 

 kindly forward any notes they may have made on the subject, or give us the 

 benefit of their suggestions. The author of the succeeding paper appears 

 equally puzzled with ourselves, and equally unable to solve the question. 



