1 8 THE BLACKMOOR VALE 



giving place to oats, and the land was tending to 

 become " oat-sick." Though this was the impression 

 conveyed to us, it was difficult to justify it from the 

 agricultural statistics ; the acreage under barley had 

 certainly been slowly declining, but with no correspond- 

 ing increase in that of oats. The incidence of parasitic 

 diseases is often determined by climatic conditions 

 which escape our observation, possibly in this case un- 

 favourable seed-times had been the determining factor. 

 Moreover, there is little evidence of land becoming " oat- 

 sick " in the north, where the crop is more frequently 

 grown, often only after one or two years' interval. 



On the heavy land on the lower part of the farm 

 we made the acquaintance of a weed known only to 

 us from a casual paragraph in the text-books ; a field 

 of beans, themselves tall and strong in the straw, was 

 overtopped by the waving panicles of some big grass 

 in flower, almost as conspicuous as reeds, and in 

 patches completely hiding the beans. This was 

 "onion-couch," a form of the tall oat-grass, Avena 

 elatior, one of the commonest constituents of Hertford- 

 shire meadows, but here a weed of the arable land, 

 developing just along the surface of the ground a 

 string of small bulbs, varying in size from that of 

 a hazel-nut to that of a pea, and resembling nothing 

 so much as the Chinese artichoke, Stachys tuberifera, 

 which a few people grow in their gardens. A terrible 

 weed to deal with, because cultivator or harrow only 

 breaks up the rows of tubers, and each will give rise 

 to a new plant ; they cannot be dragged out of the 

 ground and collected like the strings of true couch, 

 and their tuberous form makes them resistant of 

 drought, so that they take a good deal of killing when 

 the land is being fallowed. In this case an infested 

 field and the weed is only really troublesome on the 



