28 THE INFANCY OF ANIMALS 



So then we have good reason for assuming that longi- 

 tudinal striping stands for more than meets the eye at a 

 first glance ; and we may safely regard such a style of 

 coloration as one which has survived from a very remote 

 antiquity. On the whole it is now characteristic rather of 

 young than adult animals. Striped adults, be it noted, 

 always produce striped young ; but more commonly, 

 among existing mammals, striped young, at any rate 

 longitudinally striped young, are> the offspring of " self- 

 coloured " parents. 



Very weH. From what we have said it might well 

 have been expected that the marsupials, as representing 

 some of the lowliest of the mammalia, would, almost 

 without exception, have displayed what we may call this 

 primitive, old-style coloration, at any rate when young. 

 Yet, curiously enough, such is not the case : on the con- 

 trary, this coloration is met with only in a very few 

 marsupials, and here in both adult and young phases of 

 development. It is found, for example, in the pretty 

 little long-snouted phalanger (Tarsipes rostratus), and 

 the three-striped opossum {Didelphys americanus) of 

 Brazil, in which a black stripe runs from head to tail 

 along the spine, and one on either side of this. Another 

 opossum has but a single black band running down the 

 back ; and one of the smaller kangaroos, or " waUabies " 

 (Petrogale xanthopus), has a single white stripe running 

 along the flank and across the thigh. But this last case 

 really hardly comes within the pale of longitudinal striping 

 from our present point of view, and probably represents 

 a more recently, independently acquired character, com- 

 parable to that of the African antelope (p. 31). 



Perhaps nowhere, among living mammals, can this 

 " ancestral-juvenile " longitudinal striping be more per- 



