266 
Mac Dougal, 
lower internodes of the stem, which were almost as long as the main 
root. The first leaf was of orbicular outline, sometimes cut nearly to 
the base, while in other specimens the first, second and sometimes the 
third leaves showed only crenation. The fourth leaf was visible on 
many of the seedlings on the above date (Fig. 1). 
Aquatic seedlings developed an axis longer than that of the terres- 
trials witli a slender main root of greater length and with fewer branches. 
The primary leaf was of a width not more than one-third of that of the 
terrestrial, not entire in any instance, but never divided to the base. 
The second and third leaves departed less from the form of the nepionic 
leaf than did the same organs in terrestrial plantlets (Fig. 2). Deve¬ 
lopment was terminated in every case in five or six months after germination 
and no adult plants were secured from 
aquatic germinations. This result in- 
dicates that the seedling was exposed 
to an extreme of conditions and the 
divergence was probably as wide as 
might be produced. The death of 
the young plants may be ascribed to 
the unsuitability of the leaves for 
photosynthesis under submersion. 
Terrestrial plants a year old were of 
course able to endure submersion and 
produced finely dissected leaves com- 
parable in spread and length with others 
unfolded in the air. So far as the 
forms of the leaves are to be taken 
into account the diversity noted above 
was well within the ränge of Variation noted by Shull in seedlings grown 
as terrestrials. 
Some experimental cultures were begun in 1902 which might 
afford further opportunity for testing the generalizations noted above 
and also yield some Information bearing upon the transmission of 
environic effects to successive generations. The present contribution is 
concerned with the first named subject: the inheritance of environic 
effects, or the transmission of „acquired“ characters is being treated in 
an extensive series of cultures at the various plantations of the Depart¬ 
ment of ßotanical Research of the Carnegie institution of Washington, 
and it would not be profitable to discuss the fragmentary results now 
available. 
Fig. 2. Seedlings of Sium germinated 
as aquatics. 
