I 



Miscellaneous, 355 



orders. Many carnivorous species, which seek their prey at night, 

 will also find advantages in such protective colours, for thus they 

 will more easily escape the notice of their prey. Hence many 

 nocturnal carnivores are black or nearly so, as the mink, fishes, 

 some bears, &c. The same principles will apply to birds, reptiles, 

 fishes, and to insects, both in their larval and adult states, for many 

 members of all these groups are very active at night and hide away 

 in holes or beneath dense herbage by day. Moreover, large numbers 

 of birds, fishes, and insects, that are active by day, rest in exposed 

 situations at night, and are thus liable to be destroyed by nocturnal 

 enemies. Most small birds roost in trees, bushes, or reeds, and 

 therefore need protection while sleeping. Most small fishes, that 

 are quiet at night, rest among sea-weeds, grasses, and stones, or 

 else directly upon the bottom, exposed to the attacks of many 

 nocturnal carnivorous species. The struggle for existence is severe 

 among such species. It is to be expected, therefore, that instances 

 of nocturnal protective coloration will become numerous when 

 looked for. The chief object of the present paper is to call the 

 attention of more observers to this subject. 



In many cases the same colours are equally protective in daylight 

 and at night. This is the case with the green colours, so often 

 seen in the plumage of birds that live among foliage, and with the 

 various shades of brown and grey, — common colours of birds, and 

 mammals that live on the ground, among rocks or dead leaves, and 

 of those that live on or among tree-trunks. The same applies to 

 the white colours of mammals and birds in winter and in the arctic 

 regions. But there are many colours that are not in the least pro- 

 tective by day, yet are eminently so by night. In general, the 

 black and very dark colours, common in mammals, birds, and insects, 

 are protective at night and not by day. One of the most obvious 

 eff"ects of moonlight is to give very strong or black shadows, in 

 which black or dark animals become invisible, or nearly so. This 

 invisibility is often increased by sharply contrasted stripes or 

 patches of white or light yellow, which look like patches of moon- 

 light falling across a dark shadow, and thus serve to break up the 

 outlines of bird or beast that might otherwise be recognized. 

 Transverse black or dark brown bands on fishes that rest among eel- 

 grass or sea-weeds tend to render the outlines of the fish indistinct, 

 because they look like the shadows and shaded surfaces of the 

 weeds. Black fins and tails have a similar effect in concealing or 

 destroying the outline of fishes. The striped colours of the tiger 

 have the same effect when it lives among the stalks of reeds, etc., 

 and are probably much more effective in twilight or moonlight than 

 by day. The same is true of the spotted pattern of the leopard, 

 panther, and jaguar. 



A great number of small nocturnal mammals, belonging to diverse 

 groups, have dark grey and greyish-brown colours (mouse-colours), 

 which are highly protective at night, but are usually not at all so 

 in the daytime, for such colours are conspicuous among the green 

 herbage which they frequent and on which most of them feed. 

 Moreover, nearly all such mammals hide away in holes in the day- 



