122 



REPORTS ON INVESTIGATIONS AND PROJECTS. 



United States Geological Survey, 

 Division of Physical and Chemical Research. 



[Report'of Analysis No. 2463. Material received from A. G. Mayer. Water from 2 miles off Loggerheap 



Key, Tortugas Islands, Gulf of Mexico.] 



Examined by Geo. Steiger and reported June 23, 1910. 



F. W. Clarke, Chief Chemist. 



Prof. Henry S. Pratt announces his discovery at Tortugas of the only 

 trematode known to have a complete intestinal tract. 



Dr. Frank A. Stromsten collected a large number of embryos of the log- 

 gerhead turtle and injected the blood-vessels or the lymphatics with india- 

 ink. He believes that the lymphatic system of turtles is constituted largely 

 by the formation of mesenchymal spaces and their subsequent fusion into 

 larger channels. He believes that the lymph-spaces are not connected with 

 the blood-system. 



Prof. David H. Tennent repeated and verified his discovery of a method 

 for the control of dominance in hybrid echinoderms by a change in concen- 

 tration of OH ions in the sea-water. He thus furnishes proof of the possi- 

 bility of controlling the appearance of certain characters by a change in 

 environment. He gathered abundant material for the much-desired study of 

 the cytological aspects of this important question. The great care which 

 he displayed and the many precautions he took to insure against contamina- 

 tion of the sea-water by sperm, etc., cause me to believe that his results may 

 already be accepted as proven. 



Prof. W. L. Tower is continuing his studies with more hope of ultimate 

 success than ever before, but prefers at present not to report on his work. 



Prof. A. L. Treadwell continued his studies of the Annelids, especially 

 the Eunicidae of Tortugas, and a number of colored drawings to illustrate 

 his purposed monograph were made by Mr. Morita. He found that the 

 Atlantic palolo swarmed on the mornings of June 29 and 30, and the moon's 

 last quarter fell on June 29, 19 10. Unfortunately a severe illness inter* 

 rupted his research, but it is confidently hoped that he may be able to resume 

 his interesting studies in 191 1. 



Dr. T. Wayland Vaughan continued his studies of the cecology of coral- 

 reefs and the conditions affecting the growth and associations of corals. He 



