194 
P' arkin.—Observations on 
The purpose of the present paper is to draw attention to 
some of these observations and experiments with regard 
to their general botanical interest; to describe other observa¬ 
tions bearing on latex ; and to conclude with a few remarks 
and suggestions on the origin and functions of laticiferous 
tissue. 
A word of apology is perhaps needed for the somewhat 
disconnected nature of the observations, which are, as it were, 
the outcome of what was fundamentally an economic study 
of rubber-plants. 
There was not time to carry out more detailed work on the 
function of latex on the spot, and many of the matters 
touched upon can no longer be prosecuted at home with 
the same ease. 
All remarks, unless distinctly stated to the contrary, apply 
to rubber-plants growing in Ceylon. Some of these may 
seem not altogether to tally with observations made on these 
plants elsewhere, thus admitting the possibility of the latex 
changing its character when the plants are moved from their 
natural habitats. 
The paper is divided into seven parts, each dealing with 
a more or less distinct feature relating to latex, and concludes 
with remarks on its functions :— 
I. Proteids and the coagulation of latex. 
II. Oxydases in latex. 
III. The carbohydrates of latex. 
IV. Difference in properties between the latex of young 
and old organs of the same plant. 
V. The effect of wounding on the flow of latex. 
VI. A peculiarity in the exudation of latex from the 
severed base of the petiole of Hevea brasiliensis 
and Plumiera acutifolia. 
VII. A special laticiferous system in the developing seed of 
Hevea brasiliensis. 
