130 THE VICTORIAN NATURALIST. 



enjoy the luxury of legs, and some of them have a good many, 

 rush round wildly, butting each other and everything in their way, 

 and end in a general stampede for underground retreats from the 

 region poisoned by sunshine." 



It is this hidden fauna, whose members are characterized 

 above all things by their hatred of the light, that I wish more par- 

 ticularly to dwell upon to-night. It is composed of animals from 

 numerous and divers classes — worms, insects, centipedes, mol- 

 luscs, and so forth, and it offers a rich harvest to any field 

 naturalist who will take the trouble to reap it. 



Some of these light-abhorring, lowly forms of life are excep- 

 tionally interesting as representatives either of now almost extinct 

 groups, or of groups which are not characteristically terrestrial at 

 all, but marine. These refugees or exiles, if I may so term them, 

 are driven by competition or by the necessities of their organiza- 

 tion to seek for shelter in the most obscure and inaccessible places 

 which they can find. Were they to venture into the open air in 

 broad daylight they would never be able to hold their own in the 

 struggle for existence against the more highly specialized or better 

 adapted animals by which they would be surrounded, or, in the 

 case of the representatives of marine groups, their soft and some- 

 times almost gelatinous bodies would be shrivelled up by the 

 scorching heat of the sun. As an example of a representative of 

 an ancient and now almost extinct group of animals which has 

 been driven by competition to conceal itself, I need only mention 

 the singular caterpillar-like Peripatus. This unfortunate creature, 

 supposed to more or less closely represent the ancestor alike of 

 worms and insects, has been driven literally to the uttermost ends 

 of the earth, being now found hiding away under logs and stones 

 at the Cape of Good Hope, in Australia, New Zealand, South 

 America, and the West Indies, while absent from the rest of the 

 earth's surface. I shall have occasion later on to speak more in 

 detail of some samples of typically marine groups which I found 

 hidden under logs and stones at Walhalla. 



It must not be thought that the animals which live under logs 

 and stones in the daytime necessarily spend the whole of their 

 lives in such situations, for this is by no means the case. Some 

 of them, such as Peripatus and the Land Planarians, come out at 

 night and move about actively in search of food, which they have 

 various strange and ingenious methods of obtaining, while in the 

 daytime they lie coiled up and doraiant in their hiding' places. 

 Nevertheless their typical dwelling-place is in such hidden crevices 

 as I have described, and the fact that they come out at night to 

 look for food no more proves the contrary than the fact of one's 

 wife going round to the butcher's to buy a leg of mutton proves 

 that she habitually lives in the open air. 



