314 Nutrition and Selection. 
whorls. This character of the stem, which must be defi- 
nitely determined by microscopical examination, can, how- 
ever, be predicted with sufficient accuracy by the thick- 
ness of the shoot. Of course, the same relation obtains 
in the summer when the contrast strikes the eye far more 
forcibly, and then we see that the lateral branches of 
ternary and quaternary stems have almost without ex- 
ception decussate leaves, obviously because they are the 
weakest of all. 
If the plant is taken into cultivation it is easy to mod- 
ify the proportions of the various sorts of stems by suit- 
able treatment, although vegetative methods of propaga- 
tion alone are employed; but it must be remembered that 
the buds for the following year are already completely 
laid down in October, and that the disposition of their 
leaves is therefore finally decided at that time. The ac- 
tual disposition in any given year is therefore deter- 
mined by external conditions which prevailed in the pre- 
vious year. 
The curves in Fig. 58 are plotted from observations 
which gave the following results. In March 1890, 1 planted 
out a group of rhizomes in a favorable position in my 
garden, and in June I noted the two-, three- and four- 
whorled stems, which therefore had been laid down under 
the influence of the unfavorable conditions which ob- 
tained in 1899. In the following summer I repeated the 
observations and thus formed an estimate of the effect 
of growth under more favorable circumstances (better 
soil and more light). The results were: 
RECORDS FOR WHORLS 2- 3- 4-MEROUS TOTALS 
Summer, 1890 35 21 2 58 
1891 17 40 10 67 
The apex is seen to be shifted from stems with oppo- 
