4i; 
the cells of Euphorbia splendens. 
exceedingly difficult to apply, as they were dissolved in any 
but very weak nitric acid. With Loew’s ferrocyanide-test 
I sometimes obtained a faint blue, very different to the deep 
clear blue given by the proteid masses of the stem. Perhaps 
the best hypothesis is to consider them as bodies very closely 
allied to proteid, but not answering to all the tests for it. One 
might perhaps compare with them mucin, which gives the 
characteristic proteid-reaction with the xanthoproteic test, 
but not with any other. Moreover since it is probable that 
nitrogenous food-material travels from one part of the plant 
to another in the form of glycines, we may provisionally 
regard these bodies as intermediate between the true pro- 
teids which constitute the nitrogenous reserve material, and 
the glycines which diffuse from cell to cell. 
This view is supported by the fact that they disappear in 
a starving leaf. 
The question naturally arises, What is the value of these 
proteid masses in the economy of the plant ? With a view to 
answering this I made several observations. The very nature 
of the substance makes it probable that they are of im- 
portance to the plant as reserve material, and all my observa- 
tions tended to support this view. I took some quite small 
cuttings from a plant of Euphorbia splendens and grew them 
with a strong bottom heat, so that they might form roots 
rapidly. The plants were then cut in half longitudinally and 
a thin slice treated with hot Millon’s reagent. The distribu- 
tion of proteid could then be observed macroscopically by the 
distribution of the red colour. The base of the stem was 
much redder than the apex, owing to the quantity of proteid 
required there for the growing roots : whereas under normal 
conditions the apex, where cell-division is going on, is more 
plentifully supplied than any other part of the stem. 
I then applied a macroscopic proteid-test to the leaves. 
They were treated thus : — decolourized with alcohol, the 
cuticle carefully removed with strong and hot hydrochloric 
acid, and Loew’s ferrocyanide-test applied. This treatment 
was applied to two similar leaves of two similar cuttings, 
