228 Notes . 
a continuous excretion into the tissue of the style to act upon the 
reserves deposited there. 
In addition to this excreted diastase, in certain cases the style itself 
secretes the same enzyme, the quantity being greatest while the style is 
young and diminishing after fertilization has been effected. 
Besides starch, styles of various plants were found to contain cane- 
sugar, maltose, and possibly glucose. 
The nutrition of the tube is consequently a process in which both 
the grain itself and the tissue through which it grows take a part ; 
both contain reserve materials and enzymes, though the latter are 
much more abundant in the pollen than in the styles. 
The absorption of nutritive material by the tube in most cultures is 
followed by an increase in the amount of reserve material deposited 
there as starch. In some cases (as Zamia) the resting grain contains 
neither starch nor diastase. On its absorbing sugar-solution, however, 
starch makes its appearance, and later, diastase can be detected. 
The formation of the enzymes is therefore largely helped by the 
absorption of nutriment, which seems to stimulate the pollen-grain to 
produce them. 
This investigation was carried on in the Jodrell Laboratory of the 
Royal Gardens, Kew. 
J. REYNOLDS GREEN, London, 
BOTANICAL NOTES, No. 6 : ON THE EXTRA-FLORAL 
NECTARIES OF ALEURITES. — It seemed possible that an 
examination of the relations which laticiferous tubes bear to the nec- 
taries of a plant, might throw some light on the vexed question as to 
whether the tubes conduct carbohydrates or not 1 . I selected for 
observation a plant of Aleurites cor data (Euphorbiaceae) which was 
growing in the gardens at Whampoa. 
Aleurites cor data has large, long-stalked, palmati-lobed leaves. The 
large veins terminate in the angles between the lobes, and at the end 
of each vein stands a sessile nectary. In addition, erect, stalked 
nectaries are situated on the petiole at its point of junction with the 
lamina. 
Some of the leaves of this plant are not lobed, but are entire and 
1 See papers by Dr. Scott, and by myself (with literature). Annals of Botany, 
VoL iii. 1S89. 
