24 EXPERIMENT STATION RECORD. 



rabbit (L. californicus), which, according to recent investigations is 

 restricted entirely to the region west of the Sierra; the black-tailed 

 rabbit or Texan jack rabbit ( />. texiamis); the black eared jack rabbit 

 or eastern jackass hare (L. melanotis), found on the Great Plains from 

 eastern Kansas to the Rocky Mountains and western Texas; Allen's 

 jack rabbit (L. alleni) of the deserts of southern Arizona and Sonora; 

 and the Bio Grande jack rabbit ( /.. merriami) of tbe lower Gulf coast 

 and the Rio Grande region as far as the mouth of Devils River. 



Abundance and rapidity of increase (pp. 24-L'9). — In this chapter it is 

 shown that the breeding habit of the rabbits is such (on an average 

 three per litter and a litter every three months) as to make the animals 

 increase with extreme rapidity, though the evidence on hand does not 

 substantiate the view that the rabbits breed every six weeks in the 

 year. Each species seems to have a regular breeding season and a 

 definite period of rest, for no data are at hand that show that the young- 

 are born within the United States during the months of October, 

 November, and December. But it may be said that the period of ges- 

 tation is about thirty days and that it takes about two months for the 

 young tn reach maturity. The practical bearing of these facts is more 

 or less obvious. Drives or hunts for the extermination of rabbits should 

 take place before the beginning of the breeding season. In southern 

 California they should be made in December, January, February, or 

 early in March; in Colorado and Utah, the 1st of February; in Idaho, 

 somewhat later. 



Injury to crops and means of protection (pp. 30-35). — The rabbit 

 attacks most garden plants and the bark of orchard trees and seldom 

 ignores alfalfa. Five jack rabbits, it is estimated, consume as much 

 food as one sheep. The method of protection advised is the construc- 

 tion of fences of boards or wire about fields, the use of burlap, and 

 whitewash on single trees. 



Methods of destruction (pp. 36-4G). — The method of inoculating with 

 chicken cholera or with the so-called tin tinallogy disease and the prop- 

 agation of the bladder worm and the rabbit scab [Sarcoptes cuniculi), 

 rabbit measles (Gysticercus pisiformis), and the liver coccidium (Coc- 

 cidium oviforme) as tried in Australia is briefly noted, with the com- 

 ment that the diseases caused by parasites offer little hope as a means 

 of destruction. 



Of the various methods of poisoning, the use of strychnin is thought 

 most worthy of recommendation. Paris green, Loudon purple, lead 

 salts, tartar emetic, barium carbouate, and sulphate of iron and corro- 

 sive sublimate, on the other hand, have not been found successful. 

 Phosphorus has been advocated, and means of using it are described. 



The bounty methods as followed in Arizona, California, Idaho, Kan- 

 sas. Nevada, Oregon, Texas, Utah, Washington, and Australia and the 

 amount of money expended are briefly noted. 



The natural enemies of the jack rabbits mentioned are the barn owl 



