156 



Field Ah^fes. 



different rookery trees in this parisli. I examined these fallen 

 constructions, and could not help admiring- the skill and 

 ing-enuity with which they w^ere built. Some were so well 

 entwined that, ; after a fall of 40 feet they were practically 

 sound. Speaking- generally, the twig- construction, both the 

 larger bottom, layer and the smaller upper binding-, was of 

 hedg-e Whitethorn [CratcEgus monogynii) cutting-s, green' and 

 supple from the trimmed or laid fences ; with here and there an 

 Ash [Fraxiims excelsior) or Wych Elm (Ulmtis montanci) \yN\^, 

 snipped or sawn off by the Rook's powerful beak. Over 30 

 years ag-o I examined nests and found them wholly constructed 

 of Ash. There was not at that time the frequent late spring 

 hedge-cutting we have now. The Iming was as purely agri- 

 cultural as the construction materials. It shows the modern 

 rook takes things easy if a supply of fitting stuff is easily 

 obtained. Twitch ( (i) Agrostis stolonifera of the arable-peat, 

 and (2) Agropyroii repeiis of the arable-clays) was the staple 

 commodity. Both these common grass-roots abounded, the 

 first being predominant. Mixed with them were Oat and Wheat 

 straw and Beech {Fagus sylvatica) leaves, the whole being bound 

 together by Sheeps' wool and dung. I mention this latter point 

 especially, for Mr. Howard. Saunder's ' Manual ' says, ' but 

 seldom — if ever — any w^ool.' Here the Rooks use a quantity.- — 

 E. Adrian Woodruffe Peacock, Cadney, Brigg, 9th April 

 1904. 



MOLLUSCS. 



Helix virgatawsLY. leucozona, at Cadney, Lincolnshire. — 



On the 2ist of March while out botanising, I took a dead speci- 

 men of Helix virgata var. leucozona on the freshw^ater alluvium 

 of Cadney Beck. It is the darkest purple violet, and far finer 

 than my Tenby specimens. Mr. Taylor verified it. Has anyone 

 any notes on the food plant or plants of this variety? — E. 

 Adrian Woodruffe Peacock. 



Slime Spinning by Sphserium corneum. — Amongst various 

 freshwater mollusca I put into a glass globe, containing water, 

 on 1st April, were some Sphceriiiiu coniciini. On the following- 

 day I observed one of these crawling up the side of the globe 

 and afterwards along the surface of the water. On Monday 

 I found it suspended for some time, about one inch below the 

 surface of the water, by means of a mucous thread. — C. S.: 

 Carter, Louth, 12th April 1904. , 



Naturalist, 



