138 



The Naturalist. 



Hampstead ponds, near London, celebrated for the researches of Samuel 

 Pickwick, Esq., of the Pickwick Club ; the other instance is a pond near 

 Weymouth, on the road to Portland. This pond is on a promontory 

 surrounded on three sides by arms of the sea, and with no navigable 

 river within perhaps 20 to 30 miles. The difficulty of the problem 

 consists in the fact that Elodea canadensis does not produce seed in 

 England, as only the female plant is found here, but propagates itself by 

 broken fragments of the stem which must be conveyed from place to 

 place in the moist state. Elodea canadensis is a good illustration of the 

 difficulty of defining a word, about the meaning of which most people 

 would think there could be no doubt, viz., an "individual." If, 

 with Owen, we consider every organism capable of maintaining an inde- 

 pendent existence to be an "individual," then every joint of the stem 

 of Elodea canadensis is an individual, since it is capable of becoming a 

 separate self-sustaining plant. If on the other hand, with Huxley, we 

 define an " individual " as the whole genetic product of a single fertilized 

 ovum, then all the plants of Elodea canadensis which have ever grown in 

 England together constitute but a single "individual," or at most only 

 so many individuals as there have been separate introductions. — H. 

 FnANKLiisr Parsons, M.D. 



Stonbchat. — In reply to Mr. Roberts, of Wakefield, with regard to 

 the stonechat, I am aware that it breeds at Wakefield, as the only one I 

 have in my collection was shot by Mr. Parkin there, where he also found 

 its nest. I still maintain that it is only an accidental visitor here. I have 

 worked this district and the moors above Halifax right up to Wadsworth, 

 and above Hebden Bridge as far as the ridge, and never found it till last 

 spring, at the top of Shipley Cxlen ; and strange to say, I had a male bird 

 brought to me on the 10th of this month, shot on the 5th on Dalton 

 Bank, within a mile from where I live. — Jas. Yarlby, Almondbury 

 Bank, March 14th. — [Mr. Varley should certainly have given some more 

 cogent reason than a bare assertion. — Eds. Nat.^ 



Stonechat near Bradford. — On the 26th Dec, a male specimen of 

 the stonechat was shot 97hilst flying over the fields about Bradford 

 Moor. It is now in the possession of Mr. Edward Beaumont. — J. W. 

 Carter, Manningham, Bradford, March 16th. 



Grasshopper Warbler near Bingley. — Mr. Butterfield, in his 

 " Notes on the Birds of Bingley," says that he has not observed the 

 grasshopper warbler in that locality. I have been more fortunate than 

 Mr. Butterfield. On July 22nd, last year, whilst walking over the moor 

 to Ilkley, with two friends, we heard its curious note on Baildon Moor, 

 about noon, and on our return journey we again heard its long monoto- 

 nous note on the edge of Bombalds Moor, near Bingley. — J. W. Carter. 



Yorkshire Mosses. — Hypnum giganteum. — Dr. Wesley is an in- 

 defatigable collector ; he now sends us a specimen of Hypnum giganteum, 

 Schpr., discovered by him growing in bogs and rills near the " Cow and 



