18 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Walker Prizes. 
The subjects selected by the Walker Prize committee for the 
annual award were : — 
1. The reactions of organisms to solutions, considered from the 
standpoint of the chemical theory of dissociation. 
2. Relations of plants to electricity. 
3. A statistical study of the relative cross-fertility between the 
varieties of a species. 
4. The chemical and physical reactions in cell narcosis. 
5. Causes of volcanic eruptions. 
6. The effects of past or present physical changes of the earth’s 
surface on the development of species ( e . g ., river work, changes of 
sea level, mountain building, etc.). 
Two essays were received in competition, and a first prize of sixty 
dollars was awarded to Prof. George E. Stone, of Amherst, Mass., 
for his essay entitled “ The influence of current electricity on 
plants” ; a second prize of forty dollars was awarded to Dr. Burton 
E. Livingston, of Chicago, Ill., for the essay on “ Ionic stimulation 
of algae.” 
The subjects announced for next year are : — 
1. The life history of any parasitic fungus. 
2. Contribution to our knowledge of the physiology of plants. 
3. Contribution to the development of some group of fossil 
organisms. 
4. Study of hybrids in animals or plants. 
5. Critical study of geographical distribution of species. 
6. A laboratory research in experimental geology. 
7. A field study of the mechanism of baseleveling (peneplana- 
tion). 
8. A research in mineral physics. 
9. A contribution to geological correlation in the United States. 
