210 THE NATURALIST IN NICARAGUA. [CL XI. 



particularly infested with them, probably because they 

 have not the strength to rub and pick them off, and they 

 must often hasten, if they do not cause their death. The 

 herdsmen, or " vacqueros," keep a ball of soft wax at 

 their houses, which they rub over their skin when they 

 come in from the plains, the small "garrapatos" stick- 

 ing to it, whilst the larger ones are picked off. How 

 the small ones would be got rid of if the skin had a 

 hairy coat I know not, but the torment of the ticks 

 would certainly be greatly increased. 



There are other insect parasites, for the increase and 

 protection of which a hairy coating is even more favour- 

 able than it is for the ticks. The Pediculi are specially 

 adapted to live amongst hair, their limbs being con- 

 structed for clinging to it. They deposit their nits or 

 eggs amongst it, fastening them securely to the bases of 

 the hairs. Although the pediculi are almost unknown to 

 the middle and upper classes of civilized communities, 

 in consequence of the cleanliness of their persons, 

 clothing, and houses, they abound amongst savage and 

 half- civilized people. A slight immunity from the 

 attacks of acari and pediculi might in a tropical country 

 more than compensate an animal for the loss of its hairy 

 coat, especially in the case of the domesticated dog, 

 which shelters with its master, has not to seek for its 

 food at night, and is protected by being domiciled with 

 man from the attacks of stronger animals. In the huts 

 of savages dogs are greatly exposed to the attacks of 

 parasitical insects, for vermin generally abound in such 

 localities. Man is the only species amongst the higher 

 primates that lives for months and years, often from ge- 

 neration to generation, on the same spot. Monkeys change 



