14 THE CONDOR Vol. XV lower animals have developed some other faculties as substitutes for color vision and binocular vision is not yet determined. Experimentation, properly con- trolled, along these lines, is difficult, but if the matter of concealing coloration is ewe r to be settled, naturalists must begin to pay more attention to the work of the experimental psychologists, testing the results of their experiments, wherever possible, by field observations. Until there is some reason for thinking that col- oration is necessary for the concealment of animals from their enemies, or that coloration would be effectual for that purpose, the doctrine, in view of all the apparent exceptions and inconsistencies, stands on rather insecure ground. There is no reason for assuming that animals'in their natural habitat appear to other animals as they appear to man. Finally, the camera does not represent animals in their habitat as they ap- pear to man, both on account of the lack of color and relief, and great reduction of scale in order to show habitat. Stereoscopic views would correct the latter, if it were economically practical to publish them, but color photography has no.t yet developed far enough for general use in the field. It is fairly safe to say that no photograph has yet been published which exhibited the animal as clearly as it was visible to the human eye. Some authors have frankly acknowledged this in discussing concealing coloration, but others have' said the opposite. Especial- ly reprehensible is the indulgence in taking photographs out of focus in order to obscure outlines and patterns, ignoring scale and perpective in paintings and drawings, and placing objects in front of one figure to obscure it in order to show that it is concealingly colored, and omitting the objects from before another figure to show that it is not, all of which have been practiced in advocacy of' the concealing coloration doctrine. SWALLOWS AND BED-BUGS By EDWARD R. WARREN N MY paper in the May-June CO?rDOR, 1912, entitled "Some North-cen- tral Colorado Bird Notes," I referred to the bellef that swallows harbor bed-bugs as ridiculous; and now I have to confess that possibly I did not know as much as I thought i did, a not uncommon failing with us all.' Some time after the paper was published, W. Leon Dawson in a very courteous letter, called my attention to the fact that he had found Cliff Swallows' nests badly in- fested with bed-bi?gs, in one case so much so that the colony had been deserted. He reported this in "The Birds of Washington," page 333- This started me to looking into the matter, something I had not done before, and as it would seem that not very many are posted on the subject, and in fact but little definite has been published that I have been able to find, I have thought it worth while to write up what little I have been able to learn about the matter, together with a few observations of my own, in the hope that it may be the means of bringing out further information. Certainly ornithologists should do their part in ascertain- ing whether or not swallows are guilty of bringing such disagreeable pests into human habitations. I found that a the true bed-bug chickens, and bats. Gedoelst, places it bug (Acanthia hirundinis), belonging to the same genus as (Acanthia lectularia), is parasitic on swallows, pigeons, It should perhaps be .stated that the French authority, L. in another genus because of certain structural differences,
