Ixodoidea, or Ticks 67 



man. At the point of penetration of the hypostome there is more or 

 less inflammation but serious injury does not occur unless there have 

 been introduced pathogenic bacteria or, unless the tick has been 

 abruptly removed, leaving the capitulum in the wound. Under the 

 latter circumstances, there maybe an abscess formed about the foreign 

 body and occasionally, serious results have followed. Under certain 

 conditions the tick, in various stages, may penetrate under the skin 

 and produce a tumor, within which it may survive for a considerable 

 period of time. 



Ixodes cookei is given by Banks as "common on mammals in the 

 Eastern States as far west as the Rockies." It is said to affect man 

 severely. 



Amblyomma americanum, (fig. is8e), the "lone star tick," is 

 widely distributed in the United States. Its common name is derived 

 from the single silvery spot on the scutum of the female. Hunter 

 and Hooker regard this species as, next to Boophilus annulatus, the 

 most important tick in the United States. Though more common on 

 cattle, it appears to attack mammals generally, and "in portions of 

 Louisiana and Texas it becomes a pest of considerable importance to 

 moss gatherers and other persons who spend much time in the forests." 

 ' Amblyomma cajennense, noted as a pest of man in central and 

 tropical America, is reported from various places in the south and 

 southwestern United States. 



Dermacentor variabilis is a common dog tick of the eastern United 

 States. It frequently attacks man, but the direct effects of its bite 

 are negligible. 



The " Rocky Mountian spotted fever tick" {Dermacentor andersoni 

 according to Stiles, D. venustus according to Banks) is, from the view- 

 point of its effects on man, the most important of the ticks of the 

 United States. This is because, as has been clearly established, it 

 transmits the so-called "spotted fever" of man in our northwestern 

 states. This phase of the subject will be discussed later and it need 

 merely be mentioned here, that this species has been reported as 

 causing painful injuries by its bites. Dr. Stiles states that he has 

 seen cases of rather severe lymphangitis and various sores and swell- 

 ings developing from this cause. In one case, of an individual bitten 

 near the elbow, the arm became very much swollen and the patient 

 was confined in bed for several days. The so-called tick paralysis 

 produced by this species is discussed in a preceding chapter. 



