28 



THE YOUNG NATURALIST. 



by many plants. In passing through 

 a pasture field it is very easily to be 

 seen that tlie leaves and stems of the 

 bitter, biting buttercups are avoided by 

 cattle. The accumulated experience 

 of untold bovine generations who 

 suffered from blistered tongues caused 

 by these irritant juices has become 

 concreted into what we call instinct, 

 that by some sense, probably smell, 

 teaches them what to eat and what to 

 avoid. Cases of animals being poisoned 

 by eating noxious plants growing in 

 their native pastures are comparatively 

 rare. "Out when English cattle were 

 imported into Australia, the flora was 

 so different that deaths often occurred 

 through eating poisonous plants, with 

 which they were unfamiliar. Another 

 curious fact has been recorded, in 

 certain States of America it has been 

 noticed that in herds of pigs feeding 

 in the pastures, the white ones were 

 often poisoned by eating the roots of a 

 certain plant, whilst the black ones 

 avoided it and escaped. The fact was 

 deemed inscrutable, till recent research 

 has proved that in the black pigs the 

 olfactory apparatus was more fully 

 developed than in his black brothers, 

 so that by his more acute sense of 

 smell he was able to avoid the deleteri- 

 ous plant. We cannot speculate here 

 as to the relative superiority of man- 

 kind, but who could doubt that under 

 natural conditions in that district white 

 pigs would soon have become extinct. 



As the outward obvious defences of 

 prickles, &c. disappear under cultiva- 

 tion, so the natural juices of plants 

 often lose their natural acridity and 

 noxious qualities when grown under 

 artificial conditions, such as celery for 

 example. Another characteristic of 

 plants, which if not exactly defensive 

 is at least most potently preservative 

 of the individual, and the race, is the 

 tendency to produce fresh shoots when 

 cut or eaten down. This is particularly 

 noticeable in grasses which being the 

 staple food of many animals are so 

 liable to be eaten up before the period 

 of flowering, and would therefore run 

 a great risk of being speedily extirpated 

 were it not for this provision, the more 

 they are browsed over the more numer- 

 ous do the stems become. Somewhat 

 similiar is the formation of the swollen 

 bulbous roots in dry seasons or 

 peculiar soils in plants which are not 

 normally possessed of them. Such 

 are the necklace-like roots of the false 

 oatgrass so troublesome to the farmer 

 in his tillage fields. 



There can be no doubt that the 

 penetrating odours which emanate 

 from many plants exercises a powerful 

 protective influence. Strong-smelling 

 plants, such as the mints, ragworts, 

 &c, are rejected by grazing animals, 

 although they fall a prey to the omni- 

 vorous slugs and various caterpillars ; 

 even these, however, have their favour- 

 ites and aversions, and it is remarkable 



