ECONOMIC ZOOLOGY ENTOMOLOGY. 751 



referred to above, regarding tlie possibility of checking blister rust (Cronartmni 

 rihicolum or Peridcrmium strobi) on pine by employing for this purpose its 

 parasite, T. maxima. 



The dry rot question, Moormann (Gsiidhts. Imjcn., 38 {1915), No. 18, pp. 211- 

 21.'f) — This is a reply to Falck on the same subject (E. S. K., 33, p. 151). 



ECONOMIC ZOOLOGY— ENTOMOLOGY. 



Laws relating to fur-bearing animals, 1915, D. E. Lantz (U. S. Dept. Agr., 

 Farmers' Bui. 706 {1016), pp. 24). — A summary of laws in the United States 

 and Canada relating to trapping, protection, propagation, and bounties. 



Cottontail rabbits in relation to trees and f araa crops, D. E. Lantz ( U. 8. 

 Dcpt. Agr., Farmers' Bui. 702 {11)16), pp. 12, figs. 5). — A discussion of the dam- 

 age caused by cottontail rabbits, and preventive and remedial measures therefor. 



Further experiments on the effect of low temperatures on the frog, A. T. 

 Cameeon {Proe. and Trans. Roy. 8oc. Canada, 3. scr., 8 {1915), Sec. IV, pp. 261- 

 266). — The data presented led the author to the following conclusions: 



" The death temperature of Ra)ia pipiens from cold is —1.25° ±0.15° C. 

 [29.75°±0.27° F.]. There is no climatic adaptation, nor any periodic adaptation 

 due to hibernation, in R. pipiens. The cause of death is a specific temperature 

 effect on the coordinating centers of the central nervous system. Those con^ 

 trolling lung respiration may be specially concerned. Frogs surviving degrees 

 of cold such as those occurring during a Manitoban winter do so below the 

 surface, near the margins of springs, and are themselves subjected to tempera- 

 tures below the freezing point of water. There seems to be a slight variation 

 in the death temperature from cold of different species of frogs, amounting to 

 some tenths of a degree Centigrade. Fi'ogs heated rapidly to normal room 

 temperature from a temijerature just below the freezing point of their body 

 fluids (and not itself capable of causing death) are thrown into a peculiar 

 hypersensitive condition, in which cessation of lung breathing takes place for 

 long periods." 



Snakes and their value to the agriculturist, R. W. Shuteldt {Sci. Amer. 

 Sup., 80 {1915), Nos. 2082, pp. 3U, 3.'f5, figs. 7; 2085, p. 393).— Attention is called 

 to the importance and value of snakes in the destruction of field mice. In a 

 discussion of this paper which follows, W. H. McClellan reports field observa- 

 tions which indicate that the author's estimate of the number of mice con- 

 sumed by a snake is much too high. 



The cuticula of insects as a means of defence against parasites, W. R. 

 Thompson {Proc. Cambridge Phil. Soe., 18 {1915), No. 2, pp. 51-55). — This is 

 one of a series of papers reporting the results of studies of various biological 

 questions connected with entomophagous parasites (E. S. R., 33, pp. 157, 855; 

 34, pp. 553, 557). 



The interrelation of the phagocytes and parasites of arthropods, W. R. 

 Thompson {Bui. Sac. Zool. France, JfO {1915), No. 1-3, pp. 63-6S, fig. 1).—In 

 continuation of the studies noted above the author presents tlie results of in- 

 vestigations of the phagocytic reaction in natural and experimental parasitism. 



An improved collecting bottle, C. N. Ainslie {Psyche, 22 {1915), No. 6, pp. 

 211, 212). 



The calibration of the leakage meter, C. W. Woodwoeth {California Sta. 

 Bui. 264 {1916), pp. 231-234, fig. l).—lt is pointed out that some leakage meters 

 are so inaccurate that they are unsuitable for use as guides to dosage. The 

 accuracy may be easily tested by measuring the clamp ring and the hole of 

 the test plate. " Needles can be used to make test plates, making their meas- 



