Xl PROCEEDINGS OF THE 



again have the power of placing a disagreeable fluid over their bodies, so as 

 to render themselves unpalatable. 



The most extraordinary instances of protection were found among butterflies 

 and caterpillars. For instance, small caterpillars are green, resembling the colour 

 of the vegetation on which they principally feed, but as they grow larger and 

 become more visible to the birds they have longitudinal stripes on their bodies, 

 which make them resemble a blade of grass or the twig of a tree, and so escape 

 the notice of the birds. In the case of the privet-hawkmoth the stripes change 

 from longitudinal to obUque ones, and cause it to resemble the leaves upon which 

 it feeds. Black caterpillars are very visible, but they have a great number of 

 hairy spines upon them, which almost prick the linger as they are touched : and 

 the object of their being so visible is neither more nor less than to tell the birds, 

 " I possess an element of danger for you, and the less you have to do with me the 

 better." This power of protection runs tliroughout the whole animal king- 

 dom. The caterpillar of the swallow-tail butterfly has a most disagi'eeable flavour, 

 so that no bird will eat it, and its brilliant colour enables the birds to recognise 

 it, and avoid it. The caterpillar of the elephant moth, although possessing no 

 protective colour, owes its immunity to its ugliness, and there was an interesting 

 experiment made by "Weismaun, who tried to entice birds with seeds to a tray on 

 which he had placed one of these caterpillars ; the birds flew to the tray and 

 would not attempt to touch the seeds imtil the caterpillar was removed. Brown 

 caterpillars, which are always very visible, have hairs on their bodies which the 

 birds dislike very much ; while " geometers " resemble dead twigs upon a tree. 

 The ordinary magpie-moth is not eaten by birds, simply on accoiuit of its disagree- 

 able flavour. Some caterpillars and butterflies, although not disagreeable them- 

 selves, owe their escape to their resemblance to those which are unpalatable. 



Mr. Campbell next went on to consider how far the beautiful colours of one 

 creature are appreciated by others, and said that it would seem that most creatures 

 had a perception of colour, and he referred to the courtship of various animals, 

 and more especially to that of the bower-bird. As a general rule birds of 

 brilliant plumage — which, being very observable, are exposed to a great number 

 of animals, especially in nesting-time — have covered nests when both birds are 

 of brilliant plumage ; but when only the cock is brilliant, and the hen is dull 

 in colour — as in the case of the pheasant — the hen sits on an open nest. In 

 some few cases — as in the doterel — the female bird is much more brilliant than 

 the male, but then she neglects her nest, and leaves the male to sit on the eggs. 

 The protective colouring and retreat of one or both sexes of animals during the 

 period necessary for the rearing of their yoimg is but analogous to the close-time 

 of our game-laws. 



Although nests were wonderful productions, most of their peculiarities were 

 ti'aceable to the mechanical and physical necessities of the birds. Thus, we find 

 a certain shaped beak capable of doing certain things ; a certain length of neck 

 capable of doing other things ; while certain shaped feet are necessary for building 

 in certain places ; and according to these peculiarities we have the form of the 

 nest, while the size of it is proportionate to the size of the bird. So with the 

 materials of which the nests are composed, it will be found that the materials 

 are collected according to the habits or food of the different birds. 



Mr. Campbell next referred to the experiments of Franklin and of Tyndall 

 as to the most suitable colour of clothing for winter wear, and, alluding 

 to black men, attributed their power of enduring hot climates to the pigment 

 on their bodies. Eeferring to the chameleon, he said it was necessary to disabuse 

 our minds of thepopidar notion that it has the power of changing the colour of its 

 skin so as to resemble the objects by which it is surroimded. The variability of 

 its colour is due to the presence of two layers of different-coloured pigment, 

 which it has the power of raising or sinking, and according to whichever of them 

 is nearest to the outside of the creature, so its colour varies. Thus the chameleon 

 can only change its colour through natural laws, and when it happens that its 

 colour resembles that of the surrounding objects, so much the better for it; but 

 still it is merely an accident that it is so. 



In conclusion, Mr. Campbell remarked that all the beautiful colours in the 

 world, and the singing of the bii'ds and the sounds of the various animals, could 



