78 DARWINISM AND HUMAN LIFE 



impression of the struggle for existence we 

 cannot do better than refer to a graphic picture 

 drawn by Mr. W. H. Hudson in his charming 

 " Naturalist in La Plata." The summer of 1872-3 

 in La Plata was rich in sunshine and showers ; 

 there was great wealth of blossom ; the humble- 

 bees were very abundant ; and the season was 

 also very favourable for mice which devoured the 

 bees. " In autumn the earth so teemed with 

 mice that one could scarcely walk anywhere 

 without treading on them ; while out of every 

 hollow weed-stalk lying on the ground dozens 

 could be shaken." They were so abundant that 

 " the dogs subsisted almost exclusively on them ; 

 the fowls also, from incessantly pursuing and 

 killing them, became quite rapacious in their 

 manner ; whilst the sulphur tyrant-birds (Pitangus) 

 and the Guira Cuckoos preyed on nothing but 

 mice." The cats became wild hunters ; " foxes, 

 weasels, and opossums fared sumptuously ; even 

 for the common armadillo (Dasypus villosus) it 

 was a season of affluence." Countless numbers 

 of storks and of short-eared owls came to assist 

 at the general feast. The owls were so numerous 

 that any evening after sunset Mr. Hudson could 

 count forty or fifty hovering over the trees about 

 his house. They became destructive to birds as 

 well as mice, and although the naturalist shot 

 many to try to reduce the havoc they were making 

 among the ovenbirds, the gaps he made were so 

 rapidly filled that he grew sick of the cruel war 

 in which he had hopelessly joined. " A singular 

 circumstance was that the owls began to breed 

 in the middle of winter." " By August (1873) 

 the owls had vanished, and they had, indeed, 



