52 EXPEKIMENT STATION RECORD. [Vol.35 



of Colorado. A brief description is then given of their habits and economic 

 status and methods of combating. 



The prairie dog situation, R. K. Nabours {Kansas Sta. Circ. 54 (1915), pp. 

 //).— This abridgment of Circular 4, previously noted (E. S. R., 22, p. 457), 

 treats of the methods of combating prairie dogs. 



Meadow mice, W. L. Burnett (Off. State Ent. Colo. Circ. 18 {1916), pp. 11, 

 figs. 2). — A brief description is given of five species and subspecies of Microtus 

 found in Colorado. The food habits of the different species are so similar that 

 they ai-e treated as a whole, and brief consideration is given to their natural 

 enemies, damage in the United States, possibility of an outbreak in Colorado, 

 how to save girdled trees, breeding, and methods of combating. 



Effect of 186-515 generations of Danysz bacillus in a ten per cent decoc- 

 tion of egg albumin on the gray rat (Mus decumanus), S. S. Merezhkovskii 

 {Trudy Selsk. Kiwz. Bakt. Lab., 4 {WIS), pp. 138-U9).—A mortality of 84 per 

 cent was caused among gray rats fed upon the Danysz bacillus (generations 

 186-515), obtained by their uninterrupted culture in a 10 per cent decoction of 

 egg albumin. 



Duration of the virulence of agar cultures of the Danysz bacillus, S. S. 

 Merezhkovskii {Trudy Sclsk. Khoz. Bakt. Lab., 4 {1913), pp. 181-185). — The 

 investigations here reported show that the virulence of agar cultures of the 

 Danysz bacillus may be preserved for at least 1.5 years when kept under 

 favorable conditions. 



Experiments made in 1912 in the Government of Bessarabia with the 

 Siberian marmot, S. S. Merezhkovskii {Trudy Selsk. Khoz. Bakt. Lab., 4 

 {1913), pp. 201-236, figs. 4)- — -"^ report of experimental work with the Danysz 

 bacillus in which unsatisfactory I'esults were obtained due to the high natural 

 mortality which occurred among the rodents. 



On Giardia microti sp. nov., from the meadow mouse, C. A. Kofoid and 

 Elizabeth B. Christiansen {Univ. Cal. Pubs., Zool., 16 {1915), No. 2, pp. 23-29, 

 fig. 1). — This species causes inflation of the intestines of the meadow mouse, 

 the walls of the intestines becoming thin and flaccid and assuming a yellowish- 

 orange color in the infected region. 



Propagation of wild birds, H. K. Job {Garden City, N. Y.: Doubleday, Page 

 d Co., 1915, pp. XII-\-216, pis. 65). — A manual of applied ornithology treating 

 of practical methods of propagation of quails, grouse, wild turkey, pheasants, 

 partridges, pigeons and doves, and waterfowl in America, and of attracting and 

 increasing wild birds in general, including song birds. 



A new interpretation of the relationships of temperature and humidity to 

 insect development, W. D. Pierce {U. S. Dept. Ayr., Jour. Ayr. Research, 5 

 {1916), No. 25, pp. 1183-1191, figs. ^).— The studies here presented are based 

 principally upon records of thousands of individual boll weevils {Anthonoinus 

 grnndis and A. grandis thurberkc) made by agents of the Bureau of Ento- 

 mology of this Department in the Southwest extending over a long period of 

 years. 



Following a brief introduction and discussion of experimental methods, the 

 subject is dealt with under the headings of zones of climatic relations, effective 

 temperature, zone of inactivity, nomenclature of climatic effects on life, and 

 practical applications. The author describes his method of computing effective 

 temperatures and with a chart shows his method of determining the zone of 

 effective temperatures at a humidity of 56 per cent. A chart and data are also 

 given which show the relations of temperature and humidity to cotton boll 

 weevil activity. 



Attention is called to the fact that only in recent years has it been generally 

 accepted that each species of insect, etc., may have a different zero of effective 



