Dr. E. Crisp on the Water-Ousel. 51 



British Merulidce, all of which I have dissected, with the exception of 

 White's Thrush {Tardus Whitei), very little proportional difference is 

 observed. The length of the intestinal tube in the Redwing (T. 

 iliacus) is 14 inches; the brain weighs 16 grains, the pectoral 

 muscles 1/0 grains, the weight of the body being about 2i oz. In 

 the Fieldfare (T. pilaris), weighing -4| oz., the brain weighs 26 grains, 

 and the intestinal tube measures 22 inches. In the Ring-Ousel 

 (T. to?'quatus) , weight 3 oz. 180 grains, the alimentary canal is 

 13^ inches in length, and the weight of the brain is 26 grains ; and 

 these parts in the Missel-Thrush (T. viscivorus) . in the Blackbird 

 (T. merula), and Song-Thrush (T. musicus) are of nearly the same 

 proportionate length and weight. In the young Water-Ousel that 

 I have dissected, I observed nothing remarkable in its anatomy. 

 So that, as regards the visceral anatomy, there is no important 

 difference between the Water-Ousel and the other members of this 

 group, although among the British Merules this is the only bird 

 that feeds exclusively on animal food ; but, to show how the habits 

 of a bird may be altered in this respect, I have mentioned a young 

 Water-Ousel that was reared under a Bantam, and fed on porridge 

 (P. Z. S. 1859, p. 200). 



Some writers upon this bird have spoken of the claws as being well 

 adapted for holding on to stones and other objects at the bottom of 

 the water ; but on comparing the claws of the Water-Ousel with those 

 of the other Merulidce, it will be seen that the bird has no advantage 

 of this kind, although the comparatively blunted form of the claw 

 would lead to the inference that it is used for the purpose mentioned. 



The bones of the Water-Ousel, like those of the other British mem- 

 bers of this group, contain no air* ; and it is singular that the skele- 

 ton of the Fieldfare, Redwing, and Missel-Thrush (birds of passage) 

 should in this respect resemble that of the short-flighted Water-Ousel. 



As regards the food, I am afraid that we cannot entirely acquit this 

 bird of occasionally destroying the fry of fish ; but I know of no reli- 

 able evidence to prove that it takes the ova. In the three specimens 

 before the Society, the gizzards of all contained Entomostraca, and 

 one of them a Gordian (Gordius aqualicus). In others that I have 

 dissected, I have discovered chiefly Entomostraca and the larvae of 

 Phryganea ; indeed I have found that its food is very similar to that 

 of the young Salmon (Salmo salar). 



Mr. Gould, in his present work ' The Birds of Great Britain ' 

 (part 1 ), mentions that he examined five of these birds that were 

 shot on the River Usk, in Nov. 1859, and that no trace of spawn was 

 found in any of them ; their hard gizzards were entirely filled with 

 the larvae of Phryganea and the Water-beetle (Hydrophilus). One 

 had a small Bullhead (Coitus yohio), which the bird had doubtless 

 taken from under a stone. Mr. Gould thinks that, by destroying 

 insects and their larvae that may attack the ova and fry of fishes, 

 these birds may do great service. 



* 1 need scarcely say that some of the cranial bones of birds, like those of 

 mammals, contain air. 



4* 



