510 Mr. Rennie on the Contrivances 



a desire to be in the middest *,' corresponding exactly with 

 what I have above mentioned of the sparrows and bottle-tits. 

 It is not a little interesting thus to verify facts which were 

 observed by the ancients ; and Mr. Knapp has done so in the 

 instance of the starling now under consideration. * There is 

 something,' he remarks, 6 singularly curious and mysterious 

 in the conduct of these birds previous to their nightly retire- 

 ment, by the variety and intricacy of the evolutions they 

 execute at that time. They will form themselves, perhaps, 

 into a triangle, then shoot into a long, pear-shaped figure, ex- 

 pand like a sheet, wheel into a ball, as Pliny observes, each 

 individual striving to get into the centre, &c., with a prompti- 

 tude more like parade movements than the actions of birds f .' 



In the instance of the redbreast, the hedge-sparrow (Accentor 

 modularis t BECHSTEIN), and the wren (Anorthura communis, 

 Mini), one can scarcely imagine how any of the species 

 survive the winter, were it no more than the difficulty of pro- 

 curing food. Selby, indeed, has observed wrens to perish in 

 severe winters, particularly when accompanied with great falls 

 of snow. ' Under these circumstances/ he says, ' they retire 

 for shelter into holes of walls, and to the eaves of corn and 

 haystacks ; and I have frequently found the bodies of several 

 together in old nests, which they had entered for additional 

 warmth and protection during severe storms J.' 



My friend, Allan Cunningham, tells me that he once 

 found several wrens in the hole of a wall, rolled up into a sort 

 of ball, for the purpose, no doubt, of keeping one another 

 warm during the night ; and though such circumstances are 

 only observed by rare accident, I think it very likely to be 

 nothing uncommon among such small birds as have little 

 power of generating or retaining heat in cold weather. This 

 very circumstance, indeed, was observed by the older na- 

 turalists. Speaking of wrens, the learned author of the 

 Phy sices Curiosce says, they crowd into a cave during winter 

 to increase their heat by companionship : * Multi uno specu in 

 hyeme conduntur, ut parvus in tarn minutis corporibus color 



* Natural Historic, by P. Holland, p. 284. Ed. 1634. 



f Jour, of a Naturalist, p. 195. 

 I Illustrations of Brit, Ornith. i, 197. 



