322 CARNEGIE INSTITUTION OF WASHINGTON. 



numbers apparent throughout the period of the war. The increased 

 percentage of war material necessitated the introduction of many 

 additional subdivisions (e. g., "Aviation," "Cardio- Vascular Diseases," 

 "Evacuation and Transportation of Wounded," "Mahngering," "Mili- 

 tary Surgery," "Phthisis in Soldiers," "Reconstruction, Reeducation, 

 Rehabilitation," and "Trench Diseases"), under "Military and Naval 

 Medicine." A war supplement of 260 pages, embracing classified lists 

 of the available literature dealing with the medical aspects of the war, 

 was issued in the early fall of 1918. 



BIOLOGY. 



Mann, Albert, Washington, District of Columbia. Continuation of investi- 

 gations and preparations for publication of results of work on Diatomaceoe. 



The present investigations, begun July 1, 1919, were undertaken, 

 because of the increasing importance of these minute aquatic plants and 

 their intimate relationship to several lines of scientific investigation. 

 As the most important of the marine algse, their biological value has 

 come to be generally recognized, and a consideration of their diversified 

 economic uses indicates that their careful study will be a useful con- 

 tribution to knowledge. The plan includes several distinct lines : 



An illustrated paper is in course of preparation on the marine diatoms 

 of the Philippine and Hawaiian Islands. Although these two posses- 

 sions of the United States are of similar subtropical location, and both 

 are unusually rich in their diatom flora, they are quite dissimilar in 

 native genera and species. Neither has been previously studied with 

 any thoroughness; a monograph on the diatoms of these localities is 

 therefore desirable. It will include a large number of new species and 

 several new genera. 



A similar paper is contemplated on the marine diatoms of the 

 Panama Canal Zone, material for which was secured by the Smithsonian 

 Institution before the waters adjacent to the Atlantic and the Pacific 

 terminals were affected by transfer of species through the opening of the 

 canal. Such a paper promises to be of much value in determining what 

 changes are brought about by commercial intercourse through the canal. 



A report will be prepared on some diatom dredgings made in the 

 Antarctic by the Shackleton South-polar Expedition. The material 

 for this report is scanty; for this expedition was one of geographical 

 exploration rather than for the collection of scientific specimens. But 

 any report upon the marine life of this remote region has high value. 



A considerable collection of diatomaceous material has been made 

 along the Atlantic seaboard, chiefly in the vicinity of Woods Hole, 

 Massachusetts, and has been partly investigated. This line of work is 

 to be continued. Although its immediate purpose is to supply infor- 

 mation for a better understanding of problems connected with the 



