120 HEADWATERS OF THE PARAGUAY 



see, and evidently find it just as easy to catch prey, as 

 the jaguar and ocelot. The little fawn which we saw 

 was spotted ; the grown deer had lost the spots ; if the 

 spots do really help to conceal the wearer, it is evident 

 that the deer has found the original concealing colora- 

 tion of so little value that it has actually been lost in 

 the course of the development of the species. When 

 these big cats and the deer are considered, together 

 with the dogs, tapirs, peccaries, capybaras, and big ant- 

 eaters which live in the same environment, and when 

 we also consider the difference between the young and 

 the adult deer and tapirs (both of which when adult 

 have substituted a complete or partial monochrome for 

 the ancestral spots and streaks), it is evident that in the 

 present Ufe and in the ancestral development of the big 

 mammals of South America coloration is not and has 

 not been a survival factor ; any pattern and any colour 

 may accompany the persistence and development of the 

 quaUties and attributes which are survival factors. In- 

 deed, it seems hard to believe that in their ordinary 

 environments such colour schemes as the bright red of 

 the marsh-deer, the black of the black jaguar, and the 

 black with white stripes of the great tamandua, are not 

 positive detriments to the wearers. Yet such is evidently 

 not the case. Evidently the other factors in species- 

 survival are of such overwhelming importance that the 

 coloration becomes neghgible from this standpoint, 

 whether it be conceahng or reveaUng. The cats mould 

 themselves to the ground as they crouch or crawl. 

 They take advantage of the tiniest scrap of cover. 

 They move with extraordinary stealth and patience. 

 The other animals which try to sneak off in such a 

 manner as to escape observation approach more or less 

 closely to the ideal which the cats most nearly realize. 



