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 americanwn, (fig. 158c), 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. 
