126 SAGJC/TV A.VD MORALITY OF PLANTS. 



species of fungus, like the Fly Agaric {Amanita 

 nmscarius), the poison is intense. In the leaves of 

 Wood Sorrel (Oxalis acetosella) and the Common 

 Sorrel {Rttmex acetosa) a well-known poison, oxalate 

 of potash, is present, and so we find luxuriant clusters 

 of the green leaves of the latter in all rich pastures 

 quite untouched ; whilst those of the former plant 

 frequently monopolise the ground in damp but not 

 too dark woods. 



Citric and malic acids are neither of them 

 liked by mammals or birds, and they are usually 

 present in great abundance when such fruits as 

 plums, apricots, cherries, gooseberries, apples, pears, 

 strawberries, cranberries, raspberries, blackberries, 

 etc., are young and unripe. It is necessary they 

 should be protected in this immature state, or else 

 they might be devoured before their enclosed seeds 

 were ripe and ready for dispersion. The policy 

 of keeping off too greedy friends by the temporary 

 secretion of acids they don't like has therefore 

 proved very effectual. 



One order of widely-spread plants, the GentianacecB^ 

 is remarkable in that nearly all its species have 

 an intense bitterness. How largely this protects 

 them is shown by their being seldom eaten, even by 

 caterpillars. This bitter principle is common to 

 genera included in the order, of otherwise extremely 

 varying character, such as the Centaury [ErytJirmin 

 centaureHin), the Yellow- wort {Chloj'a perfoliata), the 



