338 
Notes . 
between the laticiferous system and the assimilating tissues. Further 
experiments confirm this conclusion ; for if the plants are grown 
under normal conditions and the latex examined before and after 
the day’s assimilation, an increase is found at the end of the period, 
as is shown by the following experiments made with Euphorbia Peplus 
in the early part of November,- 1896, e. g.: — 
Nov. 3, 1896, a bright sunny day — 
Latex collected at 10 a.m. gave *0302 grms. CuO per c.c. 
>, „ „ 4 P - M - » '°3fi » » 
A sharp frost put an end to this series of experiments. The result of 
exposure to this cold was that the plants gave no exudation of latex 
on wounding even when brought into a warm room ; on applying 
pressure a thin opalescent liquid was squeezed out. 
Further experiments were accordingly carried out with Euphorbia 
pulcherrima , with the following results : — 
Collected at 
10 A.M. 
.032 
.030 
•033 
.030 
Collected at 
4 p.m. 
.049 
•046 
•046 
.047 
grs. CuO per c.c. 
Here an increase of sugars after the day’s assimilation is evident. 
With Euphorbia arborescens very discordant results were obtained : — 
Collected at 
Collected at 
IO A.M. 
4 P.M. 
.032 
•°3 2 grs. CuO per c.c. 
•034 
•0345 
.0185 
•°*3 
•012 
•018 „ „ 
•021 
•0195 
The discrepancies in the foregoing results were found to be due to 
the fact that the latex had been drawn from different parts of the 
plant, the younger portions being richer in sugar than the older. 
When we consider that some of the chief constituents of latex are 
starch, proteids, and sugar, all substances of undoubted nutrient value, 
and that the proteids are typical circulatory forms, and that the 
quantities of sugar vary with the plant’s assimilation, it is evident that 
one function of latex is to carry reserve-materials in the plant. 
