38 Flowers and their Unbidden Guests. 



The singular composition of the flora which pre- 

 vails on pasturages near to summer farms, mountain 

 herdsmen's huts, and in all places which at recurring 

 intervals are visited for long periods by ruminants, is 

 explained in a measure by this aversion of animals to 

 certain chemical.combinations in the blossoms.^ Natu-- 

 rally those plants which are avoided develop in greater 

 plenty and spread more than those which are dis- 

 turbed in their growth, and whose flowers and leaves 

 are more or less injured by grazing animals. The 

 former, therefore, are the ones which strike the eye and 

 give a special character to the vegetation. Just as in the 

 neighbourhood of farms in the Puszten district in Hun- 

 gary, we find Xanthium sjpinosum, Eryngium cam;pestre, 

 and thistles coming up again and again, together with 

 Datu/ra Stramonium, Hyoscyamus, Marruhium pere- 

 grimim, etc., so in the neighbourhood of the herdsmen's 

 huts in the Alps we find species of Aconitum, Rumex 

 Alpinus, Chenopodium Bonus - Hen/ricus, AlchemUla 

 vulgaris, growing together with Cirsium spinosissi- 

 mum in a confused mass; and many of the much 

 grazed mountain pastures in the central Alps are 

 covered almost exclusively with the luxuriantly green 

 fan-like tufts of the parsley-fern, together with 

 Nardus stricta, species of Euphrasia, Rhododendron 



^ The result, however, is also partly determined by the inti- 

 midating action of other protective appliances, which will be de- 

 scribed in future sections, and also by the form of the fruits and 

 their mode of dispersal. 



