CHAPTER XXVIII 

 ANIMAL DEFENCES PASSIVE DEFENCE 



A sketch having now been given of PRECAUTIONARY MEASURES, 

 we come to the various kinds of RESISTANCE, by which the attacks 

 of enemies when delivered are met, and, it may be, foiled. 



It is clear that defence may be either PASSIVE or ACTIVE, and 

 the two cases are best considered separately. 



PASSIVE DEFENCE 



As in the case of Precautionary Measures, it may conduce to 

 clearness if we look at this matter from two different but closely- 

 connected standpoints: i.e. (i) Bodily Characteristics; (2) Special 

 Habits; (3) Fecundity, as a means of defending the species, also 

 requires consideration. 



BODILY CHARACTERISTICS OF USE IN PASSIVE 



DEFENCE 



UNPALATABLENESS AND INDIGESTIBILITY. In dealing with 

 warning coloration (see pp. 301-309), it has been pointed out 

 that unpalatable or indigestible forms are often distinguished 

 by colours and markings which are more striking than artistic. 

 Such animals, however, are liable to "experimental tasting" on 

 the part of inexperienced enemies, and though some of these, 

 if rapidly ejected on account of their objectionable properties, 

 may escape with their lives, many or most are not so fortunate. 

 Even these, however, contribute to the defence of the species, 

 as they assist in the education of enemies. At least this is the 

 current explanation, and, so far as some animals are concerned, 

 it is based on actual experiments, though whether these are 

 sufficiently numerous and extended to form a safe basis for 

 generalization has been doubted. However this may be, we 

 are on safe ground as regards those animals which are provided 



