ECONOMIC ZOOLOGY ENTOMOLOGY. 551 



heavy gumbo soil from 4 to 35 ft. iu depth, well t^aturated with water, aud 

 overlying a sandstone formation. 



The crawfish "do the greatest amount of damage just after the plant appears 

 and before secondary leaves are developed. Large fields of young cotton have 

 been destroyed in a single night. Corn also is extensively eaten, but is not 

 so badly damaged as cotton." It is stated that in badly infested areas there 

 are from 8,000 to 12,000 holes to the acre; on one plantation 27 bbls. of craw- 

 fish were picked up in a season, and the following year 13 bbls. more were 

 secured. 



Very little is known regarding the breeding habits of this injurious species. 

 "The number of young is variable, but usually increases with the age of the 

 mother, so that females which at first have only from 50 to 100 eggs, may later 

 in life produce 400 eggs or more at a time. The development of the eggs 

 requires about a month, and the young remain with their mother for from 

 one to two weeks befoi'e starting an independent life. They grow rapidly dur- 

 ing the first summer, molting about once a month, until they attain in fall, or 

 beginning of cold weather, a length of approximately 2 in. Crawfish are soli- 

 tary in habits, and 2 are rarely found in one burrow, except during the mating 

 season or when females are accompanied by young." 



Repressive measures include deep tile draining, the collection and crushing 

 of crawfish, and the use of poison. In experiments witli carbon bisulphid, 

 chlorid of lime, and calcium carbid, it was found that carbon bisulphid gives 

 the best results. The most practical and economical means of coping with the 

 crawfish problem is to kill as many as possible by mechanical means before 

 seeding, and to treat the remaining occupied burrows with poison, preferably 

 carbon bisulphid. 



Handbook of pathogenic protozoa, edited by S. von Prowazek (Handbtich 

 der Pathogencii Protozocn. Lcipsic, 1912, pt. ^, pp. 361-515+VII, pis. 7, figs. 

 36). — In this fourth part, which completes volume 1. Treponema pallidum is 

 dealt with by P. INIiihlens (pp. 361-486) ; and The Gregarines, by C. Schellack 

 (pp. 487-515). Bibliographic lists accompany both papers. 



Bibliography of Canadian zoology for 1910, L. M. Lambe (Proc. and 

 Trans. Roy. Soc. Canada. 3. scr., 5 {1911), Sect. IV, pp. 155-163) .—^ghty-two 

 titles are listed in this bibliography. 



Bibliography of Canadian entomology for the year 1910, C. J. S. Bethune 

 (Proc. and Trans. Roy. 8oc. Canada, 3. ser., 5 (1911), Sect. IV, pp. 165-176).— 

 One hundred and sixteen titles are listed in this bibliography. 



The entomological code: A code of nomenclature for use in entomology 

 (Washington, D. C, 1912, pp. 31). — The code here presented was compiled by 

 X. Banks and A. N. Caudell for the purpose of aiding entomologists in deciding 

 questions of nomenclature arising in their work. In its preparation, the 

 various codes of nomenclature were frequently consulted and used, various 

 published articles on nomenclature were referred to, and a preliminary draft 

 was submitted to many of the principal systematic entomologists of America, 

 and their opinions given consideration. It is pointed out that existing codes 

 fail to cover many points which continually arise in entomological work, or the 

 language used is of such a broad or indefinite scope as to require official inter- 

 pretation to make the meaning evident; that scarcely an entomologist has been 

 connected with the preparation of the larger codes; and that the codes pre- 

 pared by entomologists have been of restricted scope or made with certain 

 questions in view. 



A manual of injurious insects, W. B. Collinge (Birmingham, Eng., 1012, 

 pp. XX-\-268, figs. 105). — This work has been prepared with a view to directing 

 the attention of farmers, fruit growers, horticulturists, aud others to the life 



