300 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



again raised by Mr. Bouwer's account of a visit to a stone 

 cave in Namaqua Land, about twelve days from Lake Nganii. 

 On the walls of this cave are pictures of various animals, 

 drawn by Bushmen with considerable accuracy, and among 

 them is one representing an animal with a single prominent 

 horn. Mr. Bouwer was informed by an old Bushman that he 

 had himself seen the animal, and that it was very fierce, but 

 that it has now disappeared. 



A writer on the same subject, in commenting upon Mr. 

 Bouwer's observations, remarks that, in his opinion, the uni- 

 corn existed recently in Africa, and that, although not proved 

 to be extinct, the probability of its being in existence at pres- 

 ent is not very great. He rests his opinion on the general 

 accuracy of the sketches by savages in other parts of the 

 world besides Africa, and asks, if the unicorn never did exist, 

 why should native drawings of such an animal exist in Na- 

 maqua Land, Natal, the Transvaal Republic, and Cape Colo- 

 ny, all having the same general characteristics and the one 

 particular feature? 12 A, August 8, 1872, 292. 



PAEASITE OF THE BEAVER. 



Dr. Le Conte, writing from Lausanne, in Switzerland, ad- 

 dresses a communication to Nature in regard to a remarkable 

 parasite of the beaver (Platypsylla castoris), which has been 

 considered by some as belonging to the Aphaniptera, and to 

 a family equal in value to the Pulicidm (fleas, etc.), while oth- 

 ers place it as a type of a new order of insects. Dr. Le Conte, 

 however, who is well known as one of the most eminent of 

 living entomologists, after a careful study, considers that it 

 belongs to the Ooleoptera, and that it is remarkable for the 

 generic and specific peculiarities it presents. One special char- 

 acter which it shares with three other genera is the reception 

 of the antennse in cavities on the dorsal surface of the tho- 

 rax. Special attention is invited to this insect on the part of 

 those who have to deal with beavers, either in captivity or 

 otherwise, who are urged to collect whatever insects may be 

 found upon them ; and it is suggested that the capybara and 

 the musk-rat may support allied forms. The insect is not 

 supposed to feed in any way upon the body of the beaver, but 

 simply to burrow among the epithelial scales of its epider- 

 mis. It has no organs with which it can perforate animal 



