120 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



dej)redations of these crustaceans. Investigations have been begun, 

 having in view the discovery of a method of trapping the crustaceans 

 in hirge numbers and their utilization for food, or their destruction 

 in their holes by means of a deadly gas. The experiments are not 

 yet far enough advanced to warrant definite statements, but excellent 

 results have been obtained by the use of gas. 



BIOLOGIC SURVEY OF CANAL ZONE. 



The construction of a canal across the Isthmus of Panama from 

 ocean to ocean must ultimately affect the distribution of marine 

 life along both coasts, while the physical changes wrought along the 

 line of the new waterway, including the creation of a great fresh- 

 water lake, the destruction of a belt of native forest, and the inevi- 

 table introduction by commerce of new forms of both plant and 

 animal life, must also considerably change Isthmian biology. A 

 biologic survey of the Isthmus for the purpose of adding to our 

 scientific knowledge of this recently acquired strip of territory and 

 as a means of determining the nature and extent of future changes 

 seemed very important, and a plan of work was entered into in coop - 

 eration with the Secretary of the Smithsonian Institution, the Secre- 

 tary of War, and the Secretary of Commerce and Labor. Under this 

 cooperation an assistant of the Biological Survey has for several 

 months been engaged in making collections of the birds and mammals 

 of the Canal Zone as a basis for a comprehensive report upon these 

 branches. The Isthmian region is rich in both these groups, and 

 the collections alreadj^ sent in are an earnest of the rich harvest 

 of scientific data and specimens to be expected when the work is 

 completed. 



EXPEDITION TO LAYSAN ISLAND, 



One of the largest sea-bird rookeries in the world is that on the 

 island of Laysan, the most important of a series of oceanic islands, 

 some 600 miles northwest of the Hawaiian Islands, These islands 

 were set apart as a bird reservation February 3, 1909. 



About two years ago Laysan was raided by alien feather hunters 

 and a vast number of birds were Irilled for their plumage. During 

 the year the University of Iowa planned an expedition to the island 

 in order to secure material for representative groups of sea birds 

 to form part of the university museum exhibit, and the cooperation 

 of this department was sought for the purpose. The four men 

 selected by the university were appointed temporary wardens of 

 the department and, in addition to a representative series of the 

 birds of the island, they will furnish a detailed report of the present 

 condition of the rookeries, the number of birds that breed there, 

 and the efi'ect on the prosperity of the colony of the raid of the 

 feather hunters mentioned above. 



