May, 

 1892. 



TICKS. 



201 



rostrum with the terrible-looking armature of recurved hooks by 

 which it is fixed to the skin of its victim, and drop off; but when 

 irritation is felt scratching or rubbing naturally begins, and thus the 

 Ixodes is torn away by the simple process of breaking the horny 

 rostrum short off, and leaving the barbed portion in the wound for 

 nature to remove as best she may. Thus, a short time since I 

 received two lots of Ixodidae almost on the same day. One series 

 was obtained from North Africa, and had been gathered from bats ; 

 these had sucked but little, and there was not a single whole rostrum 

 among them. The others, from the Leeward Islands, were fully fed, 

 and had been carefully gathered from cattle, the rostra being 

 unbroken. People, however, naturally do not desire that the Acarid 

 should be allowed to finish its repast in peace, and the question arises, 

 cannot it be induced to withdraw its rostrum before sucking to reple- 

 tion ? M. Megnin, of Vincennes, who has studied the question, says 

 that it can, and that a drop of turpentine or benzole will cause it to 



n 



Fig. I. — Rostrum (maxillary lip) of Ixodes reduvius, female (= I. ricinus) seen from below 

 mandibles retracted. After Canestrini. One only of the cultriform palpi is drawn. 



Fig. 2. — The same part (without the palpus) of Ixodes lacerta seen from above ; mandibles 

 protruded. After Pagenstecher. 



Fig. 3. — One mandible oi Ixodes reduvius, female seen from the side. After Pagenstecher. 



be so uncomfortable that it promptly removes itself to less unpleasant 

 quarters. I am told that even a drop of oil will have the desired 

 efifect in most cases. If there be many Ticks, the question of whether 

 they are allowed to proceed with their meal, or aire cruelly removed 

 while still hungry, must be an interesting one to the host, for their 

 •capability for sucking is certainly remarkable. When fasting, the 

 male and female are about the same size. The male, however, 

 although not incapable of feeding, like the male gnat, is satisfied with 

 a moderate amount ; not so the female, which continues to suck 

 until, in some species, from a size which may almost be described as 

 microscopic, she becomes the greater part of an inch long. Professor 

 Leidy lately had the idea of weighing a considerable number of adult 

 female North American Ticks of one species fasting, and then 



