i 4 6 LOCH CRERAN. 



enables them to do a great deal in the way of patient 

 waiting for "something to turn up," seeing they are un- 

 able to do much in the more natural way of hunting 

 suitable pastures. We have been told of the amazing 

 quantities of fleas that suddenly appear in desert places 

 on the advent of humanity or any warm-blooded animals ; 

 and, therefore, these more active parasites must have a 

 similar power of waiting for a godsend. 



There have frequently appeared accounts of the dex- 

 terity of observing travellers, in determining the points 

 of the compass from the growth of mosses and lichens on 

 the stems of trees. The principal involved in their 

 calculation is a sufficiently simple one, and appeals at 

 once to the reason as a most natural reading of a very 

 likely fact. The prevailing wind of a cold country is, 

 say, from the north, and in consequence the side exposed 

 to such severe blasts must be quite denuded of the 

 surplus coating that so freely gathers on the bark of trees 

 in sheltered nooks and crannies. On the other hand, 

 one would naturally suppose that in a district where the 

 prevalent wind is from the south-west, the side exposed 

 to these genial moisture-bearing winds would be certainly 

 well supplied with the damper mosses, fostered by the 

 warmth and the moisture. Keeping these views before 

 us, we have been examining for some time back the 

 woods here, deep and sheltered, and the copse there, 

 narrow and exposed, the rough-barked trees with plenty 

 of hold and freedom of lodgment for the spores, and the 

 smooth-barked with hardened surface, and facing without 

 protection the fiercest winds that blow; but not a single 

 fraction of difference can we perceive in any one of them 

 in any direction, north, south, east, or west, except for 

 some merely individual reason, to be quite ignored by 



