230 Wild Life in Wales 



running up to about a pound in weight, and sometimes they 

 rise freely, one of the best flies being a heavy black in- 

 sect, one of the Tipulid<e> nearly related to the common 

 " Hawthorn fly " of anglers. It is often abundant here on 

 a hot day, and when blown on to the water is sometimes 

 freely taken. Trout no doubt find their way up the 

 outlet stream ; but some of them at any rate must spawn in 

 the lake, or in the mouth of the very small feeder which 

 falls into it from the rocks above, for I have seen fry 

 abundantly there in April and May. 



The channel, through which this stream flows, has been 

 artificially cut into the rock in places, and its sides built up 

 with rough stone, for no very obvious reason unless it be 

 evidence of some ancient fortification. But in a country so 

 thickly strewn with building material as this is, the making 

 of walls seems, at times, to have been something in the 

 nature of a pastime indulged in by the inhabitants. On 

 every hand, upon the mountain sides, one meets with rude 

 bits of wall, often without visible use, "beginning and 

 ending in nowhere," which seem to have been put up 

 merely because some large fixed rocks, incorporated in their 

 structure, had suggested to somebody the idea of connecting 

 them together. In a good many of the houses, and cattle- 

 sheds, fixed rocks, or huge chance stones, have been made 

 use of in a similar manner. In some cases such a rock 

 may form no inconsiderable portion of the wall of one side 

 of a building, the remainder of the lower part of the walls 

 being formed of stones, presumably rolled into position, 

 surpassing in size any that are to be met with in buildings 

 elsewhere. 



The Welshman also excels in the building of walls with 

 a gentle curve outwards, from the field to face the hill, so 

 that the top often overhangs the base in a manner which 

 makes the five-foot structure unjumpable to even the active 

 mountain sheep, and at the same time puts a very formidable 

 obstruction in the path of the pedestrian. When a rock 

 happens to lie adjacent to the wall, in such a position that 

 it affords a foothold from which sheep might jump to the 

 top of the wall, it has to be carefully bushed with thorns, or 



