JO The Naturalist in La Plata. 



diminish or increase ; the old go, and others with 

 different weapons and a new strategy take their 

 place ; and just as a skilful man " fighting the 

 wilderness " fashions a plough from a hunting- 

 knife, turns his implements into weapons of war, 

 and for everything he possesses discovers a use 

 never contemplated by its maker, so does Nature 

 — only with an ingenuity exceeding that of man — ■ 

 use the means she has to meet all contingencies, 

 and enable her creatures, seemingly so ill-provided, 

 to maintain their fight for life. Natural selection, 

 like an angry man, can make a weapon of any- 

 thing ; and, using the word in this wide sense, the 

 mucous secretions the huanaco discharges into the 

 face of an adversary, and the pestilential drops 

 " distilled" by the skunk, are weapons, and may be 

 as effectual in defensive warfare as spines, fangs 

 and tushes. 



I do not know of a more striking instance in the 

 animal kingdom of adaptation of structure to 

 habit than is afforded by the hairy armadillo — • 

 Dasypus villosus. He appears to us, roughly 

 speaking, to resemble an ant-eater saddled with a 

 dish cover ; yet this creature, with the cunning 

 which Nature has given it to supplement all de- 

 ficiencies, has discovered in its bony encumbrance a 

 highly efficient weapon of offence. Most other 

 edentates are diurnal and almost exclusively insec- 

 tivorous, some feeding only on ants ; they have 

 unchangeable habits, very limited intelligence, and 

 vanish before civilization. The hairy armadillo 

 alone has struck out a line for itself. Like its fast 

 disappearing congeners, it is an insect-eater still, 



