134 ANIMAL LIFE IN DESERTS 



environments the insects fertilize more plants than 

 the wind does ; in deserts, perhaps because winds are 

 so common and blow without impediment among the 

 sparse vegetation, fertilization by wind is much 

 commoner than fertiUzation by insects : but the 

 insects, especially the bees, flower-eating beetles, 

 butterflies, and thrips, which are often so numerous 

 among the annual vegetation, no doubt fertiUze 

 certain species of plant, though at present we have 

 no clear knowledge on this point. One remarkable 

 fact is known : Loranthus acacice, a plant related to 

 the mistletoe, grows around the Dead Sea and in 

 the Lower Jordan Valley, as a parasite upon various 

 trees : it is almost certainly fertihzed by the Sun- 

 bird (Cinnyris osm\ which probes the tubular 

 blossoms with its long, curved beak. 



According to Kobelt the Marmot {Arctomys bohac) 

 of Mongolia materially alters the character of the 

 vegetation round its colonies. The soil which is 

 thrown up round the burrows is suitable to special 

 plant types which are not common, and do not occur 

 together elsewhere in the steppe : round the colonies 

 of this rodent, and in no other place, these peculiar 

 " marmot gardens " are found. Bateson states that 

 in the very uniform steppes of Central Asia man and 

 his animals are a disturbing factor. Old camp-sites 

 can be seen from a great distance, because of the 

 patches of nettles which grow on them and not in 

 other parts of the desert. 



The dispersion of seeds by birds and animals is 

 common to all parts of the world. Seeds which are 

 particularly suited to this means of conveyance are 



