THE CANADIAN ENTOMOLOGIST. 23 



transmitter of fever germs. The creature is long-lived, and whiie it 

 requires few meals, perhaps only one in each moult, it may take the different 

 meals from different persons. Parties native or long resident in fever 

 districts often become, in a measure, immunized to the disease ; but tam. 

 pans, from feeding on the blood of such parties, might derive organisms 

 which, transferred to susceptible newcomers, would induce a serious 

 attack of the complaint. Students may shake their heads over this, but 

 the transmission of fever in this manner would not be one whit more 

 remarkable than the transmission of Texas Fever in cattle through a 

 similar agency. When studying the metamorphosis of a certain cattle 

 tick recently, I unintentionally gave this disease to a cow located far from 

 any infected area, stabled night and day, and fed entirely on dry forage. 

 The case was diagnosed by the Colonial Veterinary Surgeon, the best 

 authority in the country, so its determination admits of no doubt. But the 

 strange part is that the ticks inducing the disease must have had it trans 

 mitted to them from the mother tick ; this had been collected in a Texas 

 Fever area te?i mofiths before. 



To refer again to Argas persicus, the change in location of a settle- 

 ment affording temporary relief to the Persians may be explained without 

 considering the relief evidence of very local distribution of the pest. All 

 is, the tick only becomes abundant where its food supply is located. It 

 does not multiply rapidly, but takes its meals so infrequently that its 

 round of life is an extended one ; therefore, after a few years an abode 

 may become teeming with them. If such a place be occupied after a long 

 period of disuse, the occupant would draw a multitude of the creatures 

 from their lurking places ; the presence of a clean-skinned stranger among 

 the dirty inhabitants might also bring out the enemy in unusual numbers. 

 In the long interval between its meals, the tick secretes itself away from 

 its host just as a bed-bug does. Therefore the removal of the inhabitants 

 and their scanty belongings leaves all or nearly all of the pest behind, 

 perhaps to take a year or several years to starve to death. If the people 

 change their location simply to get away from their vermin, it is probable 

 that they look over their chattels to see that none is carried to the new 

 quarters, and thus for a while they may have complete relief. 



The apparently local distribution of O. Savigiiyi in parts of South 

 Africa may be explained as I explain that oi A. persicus. In the north- 

 west of this Colony, O. Savignyi has the name of occurring almost solely 

 in the shade of the Cameel Doom (Acacia giraffce). No experienced 



