Protozoan Cattle Fever. Texas Fever. Paludism of Cattle. 609 



cattle are excluded from the cultivated land in winter as well as 

 in summer. During warm days ovigerous female ticks, dropped 

 from the skins of such cattle, may produce eggs and larvae to 

 start a new crop in the coming summer. But as has happened 

 to the wood ticks of the North, so in the South, cultivation of 

 the soil and the exclusion of cattle for a length of time, will ex- 

 terminate the race of ixodes. 



Exclusion' of cattle for two winters and the intervening summer 

 will eradicate the ticks even in the. absence of cultivated crops. 

 To reach full maturity and propagate its kind, the tick must 

 have bovine blood: If therefore the ticks of a whole season 

 (spring, summer and autumn) are denied bovine victims, and 

 thus cut short in their development, no crop is left for the suc- 

 ceeding spring. If then a cattle pasture is divided in two parts 

 by a double fence with an intervening space of 5 or 6 feet, and if 

 the cattle are confined to one of these parts for a whole year and 

 are transferred to the second half in January after dipping or 

 smearing with ixodicide oil they may be kept entirely free from 

 ticks thereafter. That half of the pasture which is abandoned 

 in the second year, will be tick-free and salubrious in the third 

 year. 



Another resort, advised by Curtice when a large tick-free pas- 

 ture is available, is to place the infected cattle in a pen, and soil 

 them for three weeks, no longer. Then transfer them to another 

 clean pen and soil them there foir three weeks more. Then ex- 

 amine closely, and if entirely free from ticks they can be put in 

 the large clean pasture. Should they still carry a few ticks they 

 should be placed in a third clean pen for two weeks more, when 

 they will be tick-free and may be turned into the large pasture 

 without the formality of examination. This is substantially 

 based on the period of parasitism of the tick on the skin of the 

 ox, and its development from the newly hatched larva (seed tick), 

 to the ovigerous female. This period is from three to four weeks. 

 The greater number of the ticks are therefore dropped off as 

 mature ticks to lay their eggs in the first pen, while the remain- 

 der are similarly left in the second pen. As the stock leaves the 

 two pens in succession long before the deposited eggs have had 

 time to hatch out, they can take on no more ticks and emerge 

 from the second pen clean and safe. The same pens cannot be 

 39 



