( J>i ) 
. . When 1 had the Pleafare of examining the Colledh 
'ns -of Frederick Ruyfch and Albert Seh a at Amjer- 
dam^ in both which were great Variety of dilfeded 
Leaves, they made no Mention of fuch Difcovery • 
although in a Leaf from the Colledion of Ruyfch I 
could (with a Glafs) obferve the Fibres to be double 
towards the Edges of the Leaf* which at that Time 
I imagined to be an unnatural Divilion of the Fibres, 
as in decayed Sticks. 
In the mean Time, Albert Seh a having communi- 
cated the Method of diffeding Leaves to the Society^ 
by a Letter to the Prefident, I feparated the pulpous from 
the fibrous Parts of feveral Leaves after his Method ; 
when examining them by Glafies, and in Water, I found 
that each Fibre was naturally feparated into two diftind 
Fibres by a thin Stratum of the pulpous Subfiance 5 
and that this Separation was continued through all the 
Fibres and Stem of the Leaf, fo as to form two diflind 
■■’Planes of fimilar Net- work. 
Though this Duplication of the VefTels in Leaves 
feems to point out an Analogy between them and the 
Veins and Arteries of Animals', yef Tfee no probable 
Means of guefling which are the arterial and which 
the venal Fibres. 
That I might illuflrate this Matter, as it appeared 
to me, I have prepared two Leaves/ the one of an 
Apple, the other of a Cherry ; in which, as well the 
Separation of the Fibres and Stem, as the pulpous 
Subftance, by which they are naturally feparated, are 
. very obvious. See Plate II. A the Cherry-Leaf ; 
B the Apple-Leaf^ whofe Planes arepeparated. 
Both which (the Society having nothing of this 
-Nature in their Repofitory) I defire may be accepted 
as a Mark of th^Refped of their 
Mojl HurMe Affociate^ 
F. NlC H OLLS. 
■ II, 1730, 
