VETERINARY MEDICINE. 683 



Health Mont., // (1907-8), pp. 77-/.V/).— This account consists of 2 reports, the 

 first of which was transmitted January 15, 1908. the second December 12, 1908. 



In the first (pp. 87-130), the investigations conducted up to the time of 

 transmission are reported, the life cycle of the tick which transmits the disease 

 {Dermacentor venustus), exiierimental work with the tick in relation to 

 spotted fever, hereditary transmission of spotted fever in the tick, the exist- 

 ence of infected ticks in nature, tick eradication, etc., being considered. 



The second report (pp. 1.31-191) includes investigations relating to the 

 source of infection for ticks and the means by which the disease is kept active 

 from year to year. By hereditary transmission of the causative agent which 

 takes place in the tick in a certjiin percentage of cases (more than 7 per cent 

 and less than 50 per cent), it has been kept alive in some into the third genera- 

 tion. The existence of spotted fever in a number of distinct foci separated 

 by zones in which the di.sease does not occur is further evidence that some 

 source of infection for the ticks, other than man, exists in nature. 



The disease was found to be acute in the gopher or ground squirrel ; after 

 recovery from the disease their blood was free from the virus. Ticks were 

 found to transmit the disease from the guinea pig to the gopher and also 

 from the gopher to the guinea pig. Experiments with the gopher showed it 

 to be possible for this animal acting in conjunction with the tick to be re- 

 sponsible for the maintenance of spotted fever from one year to the next. 

 Studies carried on show the rock squirrel, woodchuck, chipmunk, and moun- 

 tain rat to be susceptible to s])otted fever and to serve as hosts for D. vcnustus, 

 and indicate that at least the first three as well as the gopher may, when act- 

 ing in conjunction with the tick, be effective in maintaining the disease by 

 causing its extension among the ticks. It is shown that in Idaho the infec- 

 tion is transmitted by a different species of Dermacentor and that it is less 

 virulent. 



Under the heading of hosts of ticks, the author reports that adult ticks 

 have been found to feed mainly on the larger animals, such as the horse, cow, 

 and certain of the wild animals, as the deer, elk, and mountain goat. The 

 spotted fever tick of Idaho was found on snowshoe rabbits in large numbers 

 in all stages of their development and at one time. "The gopher, rock squirrel, 

 and pine squirrel are utilized as hosts by the larvfe and nymphs to an exten- 

 sive degree, and the same is true, but perhaps to a smaller extent, of the chip- 

 munk, woodchuck. and mountain rat. Minute ticks have also been reported 

 to me as occurring on the rock rabbit." 



As regards prophylaxis, the author considers the most effective single 

 method to consist of oiling the horses, cattle, dogs, other domestic animals 

 on which this tick feeds extensively, from about March 15 to about June 15. 

 The clearing of land which affords protection to the ticks and some of the 

 small hosts on which they feed is another aid, while the destruction of the 

 small wild animals mentioned may be of value in destroying hosts for the 

 tick and possibly hosts fr)r the virus of spotted fever. 



Bibliography of trypanosomiasis, C. A. Thimm (London: Sleeping Sick- 

 ness Bur., 1909. pp. 228). — This publication contains almost complete lists of 

 original palmers on sleeping sickness au(| the trypanosomiases of man and ani- 

 mals from 1803 to March 31, 1909, and references to works and papers on tsetse 

 flies, especially Glossina palpalis. The arrangement is by authors in alpha- 

 betical order, the papers being given again under the names of the journals 

 in which they appeared. Against each original reference is an index number. 



Subject index to the bibliography of trypanosomiasis, C. A. Thimm (Lon- 

 don: Sleeping SichnGns Bur,, 1910, pp. ^7). — Tlie additious and corrections 



