250 EXPERIMENT STATION RECOED, 



cau.ubt duriiiu the ihtkkI uiul(>r rop<>i"< was 1. ")(;,().")'.). of which 93,558 were exam- 

 ined. In Oalvland. 25.SS!) were caught, of which ](i.r)!),3 were examined, 2 

 being found infected witli phii^ne. In Los Anjieles, in August, 190S, a case of 

 human plague was rejtortcd, and shortly afterwards a ground squirrel was 

 found with plague infection. During the period from September 24, 1908, to 

 April 12, 1909, 13,992 animals were killed and examined for plague infection, 

 including 4.722 ground S(piiiTels and 8,977 rats, but none was found infected. 

 In Seattle, during the fiscal year, 51,750 i-ats were caught and 48,652 examined, 

 10 being found infected. In the campaign against ground squirrels in Contra 

 Costa (\)unty, Cal., up to October 30, 44.843 squirrels had been destroyed, of 

 which 298 wer(> found to be infected. 



The plague eradicative measures (squirrel campaign) in Contra Costa 

 County, California, W. C. Hucker (Jour. Amer. Med. Assoc, 53 {1909), No. 

 2Ji, pp. 1995-1999, fig. 1). — This is a more detailed account than that previously 

 noted (E. S. R., 22, p. 153). 



The author describes the epizootic that destroyed great numbers of ground 

 squirrels in 1904, 1905. and 1900. This is sui)posed to have been bubonic plague, 

 as this disease was found in 1908 to be epizootic in these animals. In a careful 

 study of the habits of the scpiirrels {CitcUus licecliyi), it was found that tliey 

 spend the winters, that is the wet months, in the foothills, and that there the 

 young are born. They are usually collected into colonies and sometimes dig 

 very extensive l>urrows, honeycombing an entire hillside. The nest is formed of 

 straw and pieces of 'soft bark and is usually alive with fleas. Commercial 

 carbon bisulphid and poisoned wheat gave good results in poisoning the 

 squirrels. 



" Carbon bisulphid seems to be the ideal agent for tlie extermination of 

 squirrels in a jilague campaign, for the reason that it not only kills the 

 squirrels, but also the fleas on them, and in the tunnels, thus precluding the 

 possibility of infected fleas remaining to perpetuate the epizootic in another 

 colony of squirrels subsequently occupying the same burrow. . . . The poison- 

 ous agent used in treating wheat is either sti'ycbnin sulphate or cyanid of 

 potassium, preferably a mixture of the two, api)lied to wheat with a little 

 glucose, or other sweet material, and then dried. . . . Phosphorus has not 

 proved as useful in the destruction of ground squirrels as in the poisoning of 

 rats. . . . Several varieties .of traps have been experimented with, but none 

 has proved very successful." 



The squirrels as shot are shipped to the laboratory at San Francisco for 

 examination, a total of about 250 having been found up to October 1, 1909, to 

 be infected. 



Special report on the decrease of certain birds, and its causes, with sug- 

 gestions for bird protection, E. H. Forbush (Boston, 1908, 2. rd., rev., pp. 

 118, pis. 2, map 1). — A second revised edition (B. S. R., 17, p. 1088). 



Protozoology, G. X. Calkins {New York and Philadelphia, 1909. pp. /X+ 

 31/9, pis. .'i, fif/s. 125). — An introduction to the study of modern protozoology. In 

 chapter 1, the general mori)hology, the organs of locomotion and the classifica- 

 tion are considered. The following chapters are dovoted to the i^hysiological 

 activities of the protozoa : pi-otoplasmic age of protozoa ; conjugation, matura- 

 tion, and fertilization; parasitism; pathogenic flagellates (3 chapters) ; patho- 

 genic hemosporidia ; and pathogenic rhizopoda. 



An extensive bibliography is appended. 



On the relation of certain cestode and nematode parasites to bacterial 

 disease, A. E. Shipley {Jour. Ecoii. Biol., .'i {1909). No. 3, pp. 61-71, /iff. 1). — 

 A paper read before the Associatiou of Economic Biologists at Oxford, July 13, 

 1909. 



