DEVELOPMENT OF THE IXODIDZ. 69 
when feed is short and the cattle are poor. The ranchmen state that 
a heavily infested animal can often be told by the rough appearance 
of the hair. 
There are numerous instances of this tick infesting the ears of man. 
Simpson. (1901) reports a case in which two nymphs were taken, one 
from each ear of a gentleman in England who had camped in Arizona 
two months previous. The minute larve readily gain access to the 
external meatus of the human ear, where they develop to nymphs 
before causing much irritation. Intense pain may be caused by its 
presence, but usually there are no serious consequences. 
NATURAL CONTROL. 
We have observed that occasionally nymphs, which enter the 
meatus, are killed by being coated by the wax secreted in the ears of 
cattle. No natural enemies have been observed. Considerable 
moisture appears to be injurious to the nymphs and adults. 
ARTIFICIAL CONTROL. 
Dairy cattle and calves in infested districts should be frequently 
examined, the ticks removed, and some mild oil introduced into the 
ear. Townsend (1893), reporting upon this tick as observed in New 
Mexico, states that “a mixture of 20 parts of sweet oil to one of 
laudanum is sometimes poured into the ear as a remedy, but is 
of doubtful efficiency.”” Train oil, sometimes called British oil, he 
says, is highly recommended and he believes that it, as well as fish oil, 
will prove effective, but warns against the use of kerosene oil, which 
in the pure state has been known to cause temporary deafness. 
Townsend states that Dr. W. B. Lyon, of Las Cruces, N. Mex., rec- 
ommended a little chloroform or carbolic acid in sweet oil or the dust- 
ing of calomel into the ears of affected horses. 
In order to determine the value of cottonseed oil as a remedy, 
on August 26, 1908, some of it was poured into the ear of a bullock 
upon nymphs which had developed from larve applied on June 2. 
The results were negative. On September 10 chloronaphtholeum 
(1 to 75) was poured into the ears of the same animal without 
causing any of the ticks to drop. 
DEVELOPMENT OF THE IXODIDZ. 
The second of the two families, the Ixodide or typical ticks, is 
represented in this country by 8 genera, including 36 described 
species and 3 varieties. . 
As based upon their molting habits, the ixodids may be divided 
into three groups: (1) The one-host ticks, or those that pass both 
molts upon the host; (2) the two-host ticks, or those which pass the 
first molt on the host but drop for the second, and (3) the three-host 
ticks, or those which drop for both molts. 
