Seasonal Changes 



to all animals from the highest to the lowest. Ill-nurtured 

 humans are often small and stunted, and the same is the 

 case with the lower animals. An insect which in its larval 

 stage has had little or unsuitable food, will produce an 

 adult considerably smaller in size than another insect of 

 the same kind which has been fortunate enough to find 

 abundant food. There are special cases, however, where 

 fasting appears to do no harm, and other cases where it 

 seems necessary. All the parasitic insects which are 

 nourished upon blood can fast for extraordinarily long 

 periods without food ; fleas, ticks and the like can fast 

 for months, and in extreme cases for years, without a bite, 

 and this is a very wise provision of Nature, for the special 

 food of these creatures is not always easy to obtain. At 

 certain periods in the lives of some animals fasting is 

 necessary, as witness the chrysalis, which never eats, and 

 the tadpole, which fasts before it becomes a frog. 



Winter, again, with its concomitant cold, is a season of 

 fasting for many animals. The hedgehog and the dor- 

 mouse, to quote common examples, simply curl themselves 

 up in some well-prepared hiding-place and enter into a 

 long sleep, till sunny skies call them once more to activity 

 and food. During hibernation, as this winter sleep is 

 called, many of the ordinary functions of the body are 

 in abeyance, and others occur at a very much lower rate 

 than is usual. The long rest takes place at the expense 

 of stored-up fat in the tissues, for most hibernating 

 animals are decidedly plump before their winter's sleep, 

 and somewhat emaciated when they make their re- 

 appearance. 



That not only the quantity but the quality of food has 

 a marked effect upon animals is a well-known fact. It is 

 shown clearly in the case of canaries which are artificially 

 fed upon food containing cayenne pepper. The result 

 of this feeding is to produce birds with orange-coloured 

 instead of the usual lemon-coloured feathers. With the 

 seasons, again, many animals change their diet rather 



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