206 Why do Birds sing ? 



named longifolius, where that figured in Flora Grccca is named 

 repens ; and that figured ill Curtis's Botanical Magazine, bi- 

 spathaceus. It may be well to obtain tubers from both the 

 Cork habitat (IV. 28, 29. 437, 4*38. ; V. 197.) and from the 

 Cornwall one (IX. 205.), or Cornwall ones (V. 200, 201.; 

 IX. 205.), and cultivate and compare the plants, to ascertain 

 if they be of one species, or of more.] 



Anagallis cceriilea, the Question of the Distinctness, as Species, 

 of it and A. arve*nsis. (VIII. 633.) — I introduced the cserulea 

 into my garden ten years since : plenty of plants have been 

 produced from seeds that have fallen into the ground. By 

 carefully rooting out the arvensis, I have almost succeeded in 

 extirpating it : this year I had but three plants of it ; but those 

 of coerulea were numerous. — John Harvey, Druggist. Pen- 

 zance, Cornwall, Oct. 29. 1835. 



Art. XI. Queries and Ansivers. 



WHY do Birds sing f (VII. 484— 486.) — Mr. Conway's 

 second question, " Why do birds sing ? " is next to be con- 

 sidered. Although many theories have been framed to an- 

 swer this question, I had never been wholly satisfied with 

 any one of them, and thought the subject would require a 

 great deal more investigation, till I met with the following 

 passage in Mudie's Feathered Tribes, which, I think, goes far 

 towards solving this baffling problem : — " The purpose which 

 the song of birds answers in the economy of nature, is one 

 of those mysteries, which, like the difference of tint in their 

 plumage, human ingenuity has not yet been able to explain. 

 It is not, however, a mere pairing cry, because it is continued 

 till the birds break the shell, and, in some instances, till they 

 are able to fly. We may be sure, however, that it has its use; 

 and, as we can observe that the females of all birds which have 

 that cry, whether it be what we call song or not, are excited 

 when it is uttered by the male, it may be that it produces in 

 the female that heat which is necessary for hatching the eggs. 

 In ourselves, there are many sounds which make the heart 

 beat, the blood dance, and the whole body glow, we know 

 not why ; and thus we have, at least, no ground for denying 

 without proof that the other animals may be affected in a 

 similar manner. Perhaps the more philosophical way of con- 

 sidering it is, to suppose that it produces general excitement, 

 and a power of more energetic performance in all the labour 

 which the birds can undertake." (I, 245.) This extract (from 



