248 The h'ish Naturalist, [October, 



Irish Birds. 



We welcome the publication of the great work on the Migration 

 of Birds, on which Mr. R. M. Barrington, aided by Mrs. Barrington 

 and Mr. C. B. MofFatt, has been engaged for several years. The book 

 not onl)^ gives in full the reports of the committee on bird-migration 

 from iSSi to 1897, but includes elaborate analyses of the reportsfrom 

 1881 till 1897. The observations on which the reports and analyses are 

 founded were made by the Keepers of the light-ships and light-houses 

 around the Irish coasts, with the aid of printed schedules and instructions, 

 and the correctness of their identifications were checked by means of the 

 preserving of a leg and wing of the birds killed by striking the lanterns. 

 The book is published by Kdward Ponsonby, Dublin, and may be 

 obtained from the publisher or the author, price 25^-. net. Only 350 

 copies have been printed. 



The long-promised general work on the Birds of Ireland b}' Messrs. 

 R. J. Ussher and R. Warren is just issued. W^e observe that a reliable 

 record of the distribution of each species of bird in Ireland has 

 been made the primary object of the book, which contains also many 

 original observations on life, history, and habits. This book is published 

 by Messrs. Gurney and Jackson at 30^-. We hope that both works will 

 be duly noticed in our next issue. 



MAMMALS, 



The Vision of Whales and of amphibious animals 



generally. 



In reference to the interestingsuggestion of Mr. R. Lloyd Patterson, page 

 210, that whales probably have the power to ascertain the position of a 

 ball of fry by " looking round them " when at the surface so as to see the 

 birds hovering over and dipping for the fry or to hear their cries, a 

 question arises — Can the whale see when its eyes are out of water .? 



Just as in diving under water, w^e whose eyes are adapted for use in air 

 cannot see clearly, so conversely an animal with eyes suited only for 

 water could not see clearly in air. 



Are a whale's eyes "only" so suited.? To enable the human eye to 

 see clearly under v/ater it is only necessary to use a convex lens of a 

 focus correcting for the difference in the index of refraction of water as 

 compared with that of air. When a whale rises out of the water has it 

 any means of making a correction the converse of this by lengthening 

 the focus of its eyes, or can it perhaps shorten the distance between the 

 lens and retina ? This question suggests one which no doubt could be 

 more easily investigated— Can a frog see well both in air and water.? I 

 have not the honour of being a naturalist, and therefore know not if 

 such questions have been already asked and answered, but if not they 

 would seem to present an interesting field for research. 



J. Brown. 



Belfast. 



