72 BIKDS OF NORFOLK. 



hen, it is neither fry nor spawn that he is then seek- 

 ing, but on the contrary the larvae of innumerable 

 water insects, amongst which, those of the dragon 

 fly (Libellulce) , of various water beetles and of the 

 May fly* (Ephemera), are known to be especially de- 

 structive to spawn. The dissection of many examples 

 of the dipper, killed in the very act of feeding, 

 has failed to prove anything but their usefulness as 

 insect eaters, and on this point I believe I cannot quote 

 three more decisive authorities than Macgillivray, Gould, 

 and Buckland. Macgillivray remarks (Brit. Bds., vol. ii., 

 p. 59), "I have opened a great number of individuals 

 at all seasons of the year, but have never found any 

 other substances in the stomach than Lymnece, Ancyli, 

 Coleoptera, and grains of gravel." Mr. Gould also, 

 writing from personal observation, ("Birds of Great 

 Britain," part 1) says, " During my visit in November, 

 1859, to Penoyre, the seat of Col. Watkyns, on the 

 river Usk, the water ouzels were very plentiful, and his 

 keeper informed me that they were then feeding on the 

 recently deposited roe of the trout and salmon. By the 

 Colonel's desire, five specimens were shot for the pur- 

 pose of ascertaining, by dissection, the truth of this asser- 

 tion, but I found no trace whatever of spawn in either 

 of them. Their hard gizzards were entirely filled with 

 larvae of Phryganea and the water beetle (Hydrophilus). 



* Mr. Win. Brown, in his interesting little work on the 

 experiments made in hatching the ova and rearing the fry at 

 Stormontfield, on theTay, says (p. 35) "TheMessrs. Ashworth, pro- 

 prietors of the Galway fishings, experimented on the May fly, and 

 their report is ' that the larvae of the May fly are known to be 

 most destructive.' In proof of this being the case, they say ' that 

 one year we deposited 70,000 salmon ova in a small pure stream, 

 adjoining to a plantation of fir trees, and these ova we found to be 

 entirely destroyed by the larvae of the May fly, which in their 

 matured state become the favourite food of smoults or young 

 salmon.' " 



