94 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



and, with the capitulum directed downward, the support is firmly 

 grasped with the third pair of legs, these legs serving as the only means 

 of attachment while the first, second and fourth pairs are extended 

 and waved in reaching for animals which approach. 



In arranging to have made a drawing of ticks in this attitude,, 

 eleven individuals, including both sexes, were placed in a very large 

 lamp globe pressed into a box of soil and covered by a piece of gauze. 

 Small, bare sticks and grass stems were erected in the soil. Several 

 days passed during which the ticks crawled about the cage without 

 apparent purpose and then, one by one, a part of both sexes came to. 

 rest and assumed the "waiting attitude." 



It was soon observed that when left undisturbed the legs were 

 all slowly brought down in contact with the support, but when the 

 hand was passed between them and the nearest window, five feet 

 away, all the legs, excepting the third pair, were instantly extended 

 and slightly waved as though reaching for a host. The cage was left 

 in the same place, out of the direct sunshine, for about nine weeks- 

 and during that period the test was repeated very many times by 

 several persons. It was further noticed that the ticks showed a dis- 

 tinct preference for the side of the twigs toward the window, which 

 brought the dorsal surface and the eyes toward the strongest light. 

 It seems clear, therefore, that stimulation is received through the 

 eyes and probable that this tick becomes aware of the approach of 

 animals by the occurrence of shadows or by cutting off light. 



In one instance, while the cage was temporarily in the sunshine, 

 we were able to "lead" a tick across the smooth ground in the bottom 

 of the cage by suddenly casting the shadow of a pencil upon it through 

 the glass wall. The tick immediately changed the direction of its 

 movement and walked rapidly under the shadow toward the pencil, 

 avoiding the sunlight at the sides. It is well understood, and we 

 have demonstrated, that ticks avoid direct sunlight and it is pos- 

 sible that this tick was seeking protection from the sun, but it is 

 equally possible that this observation indicates another adaptation 

 for securing a host, for it is clear that in nature a suddenly appearing 

 shadow means the approach of an animal and that by following under 

 the shadow toward the sun the tick will arrive at the feet of the host. 

 We have been told by persons in Montana that after sitting on the 

 ground for a short time they have seen ticks craw^ling toward them on 

 the ground. 



Blowing the breath through the top of the cage always caused 

 the ticks to quickly extend the legs the same as when the light was cut 

 off. Suddenly blowing the hot breath into the cage sometimes caused 

 them to drop quickly to the ground. It seems to be indicated that 



