1881. ] Botany. 999 
fruit outside of the immediate radius of the tree. So like butter- 
ies do these scale-borne nuts in the air appear, that I have been 
repeatedly deceived by them. It seenis to me that the subject 
would reward the diligent study of one who combined good 
powers of observation with certain mathematical attainments. 
“ Fic. 1.—Bract, with its cluster of ripened nuts ; Fic. 2—A more frequent condi- 
on, 
I would add that usually, the nuts more or less break off before 
the disarticulation of the scale from the tree, one or two only 
remaining, and these standing somewhat at right angles to the 
main peduncle. May not this throwing of the weight to one 
Side, itself induce the revolution?—W. W. Bailey, Brown Univer- 
sity, Oct. 15, 1881. 
Tue SENSITIVENEsS OF TENDRILS.—Some years since, in order 
to measure the sensitiveness of the very fine and slender tendrils 
of Cobea scandens, I placed one evening at seven o'clock, a human 
hair about two inches in length upon an expanded tendril. ‘This 
Was done with the greatest care, so as not to produce any other 
Irritation than that due to the weight of the hair itself. Upon 
€xamination the next morning at seven o'clock, the tendril was 
found to have tightly clasped around the hair, and coiled itself 
into a tight knot. Every precaution had been taken to prevent 
interference with the experiment, so that it may be considered as 
certain that the contact of the hair was the exciting cause of the 
_ twining of the tendril. 
