i EXTERNAL FEATURES 5 



direction. Periju'tttix, therefore, is zoologically of extreme interest 

 from the fact that, though in the main Arthropodan, it possesses 

 features which are possessed by no other Arthropod, and which 

 connect it to the group to which the Arthropoda are in the 

 general plan of their organisation most closely related. It must, 

 therefore, according to our present lights, be regarded as a very 

 primitive form ; and this view of it is borne out by its extreme 

 isolation at the present day. Peripatus stands absolutely alone 

 as a kind of half-way animal between the Arthropoda and Anne- 

 lida. There is no gradation of structure within the genus ; the 

 species are very limited in number, and in all of them the 

 peculiar features above mentioned are equally sharply marked. 



Peripatus, though a lowly organised animal, and of remark- 

 able sluggishness, with but slight development of the higher 

 organs of sense, with eyes the only function of which is to enable 

 it to avoid the light though related to those animals most re- 

 pulsive to the aesthetic sense of man, animals which crawl upon 

 their bellies and spit at, or poison, their prey is yet, strange to 

 say, an animal of striking beauty. The exquisite sensitiveness 

 and constantly changing form of the antennae, the well-rounded 

 plump body, the eyes set like small diamonds on, the side of the 

 head, the delicate feet, and, above all, the rich colouring and 

 velvety texture of the skin, all combine to give these animals an 

 aspect of quite exceptional beauty. Of all the species which I 

 have seen alive, the most beautiful are the dark green individuals 

 of Capensis, and the species which I have called JBalfouri. 

 These animals, so far as skin is concerned, are not surpassed in 

 the animal kingdom. I shall never forget my astonishment and 

 delight when on bearing away the bark of a rotten tree-stump 

 in the forest on Table Mountain, I first came upon one of these 

 animals in its natural haunts, or when Mr. Trinien showed me in 

 confinement at the South African Museum a fine fat, full-grown 

 female, accompanied by her large family of thirty or more just- 

 born but pretty young, some of which were luxuriously creeping 

 about on the beautiful skin of their mother's back. 



External Features. 



The anterior part of the body may be called the head, though 

 it is not sharply marked off from the rest of the body (Fig. 1). 

 The head carries three pairs of appendages, a pair of simple eyes, 



