1896. NOTES AND COMMENTS. 375 



conversazione, namely, Professor Lippmann's colour-photographs, 

 produced in a collodion or gelatin film by interference, are not, in 

 their present state, of much use to zoologists ; but the remarkable 

 instrument which Mr. F. E. Ives showed under the name of Stereo- 

 scopic Photo-chromoscope, suggests a possible application. The 

 photo-chromoscope camera makes, at a single exposure on a com- 

 mercial photographic sensitive plate, three pairs of images which, by 

 differences in their light and shade, constitute a record of everything 

 that excites vision in the two eyes. The stereoscopic photo-chromo- 

 scope translates this record to the eyes, so that the object appears to 

 be seen through it in its natural shape and colours. It is clear that 

 this apparatus gives us an easy means of recording fleeting changes 

 of colour, and it would be of much value in the study of living animals 

 and plants. It may also be possible to use its principle for the future 

 development of those methods of colour-printing which depend on the 

 use of a series of half-tone blocks. There are, however, technical 

 difficulties in the way of superimposing many colours by means of 

 such process-blocks, and these have yet to be overcome by engravers 

 and printers. 



Some Faunal Notes on Birds. 



It is pleasant to be able to call attention to the unpretentious, 

 but none the less valuable, services of the Perthshire Society of 

 Natural Science, although we are forced to mourn the loss which its 

 members have sustained in the death of their veteran leader, the late 

 Colonel H. M. Drummond Hay, C.M.Z.S. Vol. ii., part iii., of its 

 Transactions opens with an interesting paper by J. A. Harvie Brown 

 upon the Scottish distribution of the Marsh Tit. In this connection, 

 attention should be called to the extensive and important article on 

 the same species, which has lately appeared in the same author's 

 " Fauna of Moray." Lieut. -Colonel Campbell, the Governor of H.M. 

 Prison, Perth, follows Mr. Harvie Brown's discursus on Pants with a 

 happily-conceived essay on the " Ornis " of Perthshire. This paper 

 suffers somewhat from the fact of its having been written for a popular 

 audience. It succeeds, nevertheless, in conveying a good impression 

 of the species which constitute the local avifauna. There are a few 

 mistakes. Colonel Campbell tells us, for example, that he met with 

 the Great Grey Shrike (Lanius excubitor) in Southern Spain, where no 

 doubt he really came across the Southern Grey Shrike (Lanius 

 Meridional is). But slips of this kind will not mislead an experienced 

 eye, and the tyro cares for none of these distinctions of science. 

 Taken as a whole, the essay reflects credit on an excellent naturalist, 

 and we thank him for the research which he has brought to bear upon 

 a congenial topic. 



The same number of these Transactions includes a dainty, if brief, 

 essay upon the habits and idiosyncrasies of the dipper (Cinclus 

 aquaticus), from the pen of Lieut. -Colonel W. H. M. Duthie. We 



