484 THE POPULAR SCIENCE MONTHLY. 



DEFENSES OF THE LESSER ANIMALS. 



By Pbofessob L. GLASEE. 



ALL organic beings are, in the course of their lives, subject to a 

 series of dangers and destructive influences arising from the 

 conditions of climate and temperature, and from the competition of 

 their fellow-beings, the universality and power of which are well illus- 

 trated in Darwin's phrase, "the struggle for existence." Yet all creat- 

 ures are adjusted with most wonderful art and adaptation to the con- 

 ditions of their existence and the state of the world around them. 

 Among these adaptations are the means given to the most helpless 

 animal existences for securing themselves against the depredations of 

 their enemies. It is proper to observe, in considering this subject, that 

 the protection enjoyed by the lower animal organisms is not absolute 

 and individual, but that it is generally effective principally for the 

 preservation of the species against destruction. For where peculiar 

 means of protection are given to one creature, corresponding means 

 for overcoming it are often given to another, its enemy. To the pro- 

 tective sharp sight of the rodents and birds are opposed the equally 

 sharp sight of the fox and the long range of vision of the hawk. It 

 is only in averaging the mass of such animals that we find they are 

 secured as a whole against danger, while numerous individuals are 

 overtaken by their enemies. 



Some of the higher animals illustrate the manner in which Nature 

 contrives to furnish special measures of precaution for its little-gifted, 

 unalert, unarmed, and helpless creatures. The absence of teeth in the 

 edentates is offset by shields or scale-armor ; helpless beetles are fur- 

 nished with hard wing-cases ; the pheasants, quails, and larks of the 

 fields are hidden from the keen vision of birds of prey by their earthy 

 color, birds of the river and sea-shore by their resemblance in color to 

 the sand and shingle. 



Protection is required by the lower animals chiefly against the 

 weather and against parasites and other external enemies. Frequently 

 the place of their abode is their only and ordinarily a sufficient pro- 

 tection, as is the case with earth-worms and burrowing larvae, wood- 

 worms and fruit-borers. But such animals appear to be afflicted with 

 particular enemies peculiarly fitted to hunt them out in their other- 

 wise secure fortresses in the shape of moles, mole-crickets, long-nosed 

 hedgehogs, shrew-mice, and swine, hook-billed lapwings, and sharp- 

 ton gued woodpeckers. Frequently, also, each animal is defended by 

 some special relation peculiar to its species. Insects, which in their 

 comparatively brief state of maturity are secured by their powers of 

 flight, have to be guarded, in their three previous conditions of egg f 

 larva, and pupa, against hosts of enemies to which they would other- 



