A MOUNTAIN STREAM 169 



ability to find their way home from a considerable 

 distance is due to practice in combining olfactory, 

 visual, tactile, and even muscular impressions which 

 serve as finger-posts. (3) Although ant hill may make 

 war on ant hill, there is general harmony among the 

 members of the same community, and there are certain 

 conventions, such as feeding the hungry, which appear 

 to be almost invariably respected. (4) It is, so to 

 speak, a satisfaction to the workers to labour for ends 

 which are other-regarding rather than directly self- 

 preservative or self-rewarding, but it is very interest- 

 ing to notice some recent researches which show that 

 in certain species of Ants the workers receive from 

 the larvae, when feeding them, tiny sips of a mouth- 

 secretion which seems to be appreciated like an elixir. 

 (5) Repeatedly in these studies we have referred to the 

 interlinking of the interests of different kinds of 

 creatures, and there are many illustrations to be found 

 in the ways of Ants. Thus some of them inadvertently 

 sow a percentage of the seeds which they collect for 

 food; a few of them keep Aphides, or Green Flies, as 

 domestic animals ; some of them have slaves and others 

 have pets. The circle of an Ant's life cuts many other 

 circles. It seems, for instance, that several of the 

 Little Blue Butterflies, like those flitting about on the 

 Heather, require to sojourn for a while as caterpillars 

 in the Ants' nest. We venture to refer for continuation 

 to our "Wonder of Life" (1914). 



The little valley of the stream has become a gorge, 

 and round one of the many corners, each one giving 

 us a surprise though we have followed the stream 

 many times, we come on the waterfall. It is only 

 about twenty feet high, but almost sheer, and it is not 



