58 THE entomologist's kecord. 



one's high lights, one has to chance a dense black shadow in mono- 

 chrome, or a vivid blue shadow in antochrome, where the eye sees the 

 detail and colour subdued by shadow, it is true, but neither the mono- 

 chromatic black nor the autochromatic blue. (It is not true that near 

 shadows are per .s*; blue or purple to the eye, as some artists contend; 

 distant shadows appear to be so, owing to water vapour in the atmos- 

 •phere ; but in dealing with these problems it is near objects that are to 

 be considered.) The result is that many objects stare at one from a 

 photograph that are unobtrusive in nature. 



The term " protective resemblance " to which Mr. Colthrup objects, 

 is a rough and ready way of expressing the presumed utility of the 

 coloration to its possessor, and if the coloration theories (or in fact the 

 Natural Selection Theory itself) be correct, the name is not a bad one, 

 at the same time it is incomplete and in some ways misleading. 



The vocabulary suggested by Prof. Poulton in J'^sxays on Krolntion, 

 page 226, is in every way preferable. In fact Mr. Colthrup's instances 

 of the elusive collar stud and the forceps as examples of "resemb- 

 lance" are really examples of the confusion of thought the term 

 introduces. Neither bears the slightest resemblance to its surround- 

 ings, and the difticulty arises from the bizarre coloration of the sur- 

 roundings themselves. The optical centres transmit to the brain so 

 many conflicting stimuli, arising from the many different fornjs and 

 colours observable, that the brain cannot sort them out rapidly enough 

 and clearly enough to deduce either the form or the colour of the 

 missing object. Cryptic coloring as it becomes more perfected takes 

 on in some degree the normal coloring, chequered or otherwise, of the 

 surroundings, making it still more difficult to deduce, from the stimuli 

 received by the optic centres, the nature of the object seen. Variega- 

 tion of colour alone tends to inconspicuousness, quite apart from 

 whether the colours and surroundings match or not. 



A dull grey is very difficult to see unless it be in a big mass. When 

 the mass is sufficiently large, if the grey be broken up, however crudely 

 with colours however bright, the mass is the more difficult to see. So 

 pronounced is this that the big guns in some of our South Coast forts, 

 which are all colours of the rainbow, are very difficult to see at a very 

 short distance. Even the black and white parti-coloured buoys round 

 our coast, so painted in the hope they would be thereby rendered con- 

 spicuous, are lost to sight much more quickly than a plain black or 

 plain red buoy. 



The eye certainly takes in the colour, but the brain fails to deduce 

 the form and nature of the object so concealed, for it loses its chief 

 guide to form, c/c, shadows. {Confer Prof. Poulton's remarks on the 

 inclined attitude of rest adopted by the Satyrids with cryptic under- 

 sides, which remarks are entirely in accord with my own experience, 

 and Dr. Longstaft'to the same effect, Tram. Ent. Sue. Loud., 1908, page 

 647, ff tiC'i.). If Cryptic Coloration does not serve its possessors as a. 

 means of escaping attack at rest, it is beyond my imagination entirely, 

 either as to how that coloration ever arrived at its present perfection, 

 or as to the manner in which it could be useful to its possessor. 

 (Assuming that a utility to its possessor be necessary at all, to which 

 proposition I shall advert later). (I note Lieut. Col. Manders appears to 

 agree with my views on this head). 



Mr. Colthrup says, that he cannot see that it has been proved that 



