286 ADAPTATIONS AMONG ALPINE PLANTS 



the Geums. The fruits of species of the Cleavers 

 {Galium aparine, Linn.), also a common British 

 plant, are covered with hooked bristles, the clinging 

 power of which is too well known to need description. 

 It is believed that some seeds in the Alps are 

 distributed by ants. There is a delicate little wood- 

 land plant, the Cow- wheat, Melampyrum sylvaticum, 

 Linn, (natural order Scrophulariacese, the Foxglove 

 family), common in the Pine woods, and, like the 

 Louseworts (p. 218), a semiparasite on the roots of 

 other plants. The fruits contain two (sometimes 

 only one) white, shining seeds, which are of quite 

 unusual appearance, and very conspicuous. If the 

 ripe fruit be squeezed slightly, the seeds will pop out 

 suddenly, and are shot away for some little distance. 

 If we place some of these glistening, white seeds 

 among the roots of a Pine, about which there are 

 sure to be a number of ants busily engaged, we 

 shall find that the ants instantly turn their attention 

 to them and eagerly carry them off to the nest, as if 

 they had at length found a great prize. Whether 

 the seeds of the plant are distributed only by the 

 agency of ants is as yet *'not proven." 



The Diseases of Alpine Plants. 

 It is too little recognised that plants, like animals, 

 are subject to various diseases, often infectious and 

 frequently fatal. Alpine plants form no exception to 

 the rule. These diseases arise from two sources : 

 parasitic plants and parasitic animals. The former 



