1826. ] Variation of Water in Trees and Shrubs. 425 
which appeared in Griswold’s Poets and Poetry of America 
(1842), and has been reprinted in Mr. Neill’s histories. The last 
stanza but one has direct reference to the rock I have here first 
described, and runs thus: 
“« Not long upon this mountain height 
The first and worst of storms abode, 
For, moving in his fearful might, 
Abroad the God-begotten strode, 
Afar, on yonder faint blue mound, 
In the horizon’s utmost bound, 
At the first stride his foot he set; 
The jarring world confessed the shock. 
Stranger! the track of Thunder yet 
Remains upon the living rock,” 
70: 
VARIATION OF WATER'IN TREES AND SHRUBS. 
BY D. P. PENHALLOW. 
re amount of water which highly lignified plants contain, 
particularly as influenced by season and condition of growth, 
obviously bears a more or less important relation to physiological 
processes incident to growth, and most conspicuously to those 
which embrace the movement of sap. Studies relating to the 
mechanical movement of sap in early spring at once suggest the 
question as to how far this is correlated to greater hydration of 
the tissues at the time when this movement is strongest. It was 
with a view to exhibiting this relation more clearly, that deter- - 
minations of moisture in a large number of woods, representing -Ț 
growth of one and also of ten years, collected at different seasons, 
were made in 1874.) The range of seasons was not as complete 
as could have been desired, and no attempt was made to formu- 
late a general law applicable to this question. With a view to — 
extension of data in this direction, additional estimates were un- 
ray ken in 1882, and it is the object of the present paper to com- 
ine all the results thus obtained, together with such other fact 
1 
W. S. Clark. Agriculture of Massachusetts, p. 289. 
