( *39 ) 
oppofite, when they come out in pairs, as in 
myrtle (myrtus), and many other plants. Theft 
two circumftances of leaves being alternate, 
or oppofite, furnifli conftant and invariable 
characters, w r hich are generally fo unci in. 
plants of the fame genus, or even of the fame 
natural order. Direction contains the different 
ways in which a leaf bends from it's ftem ; 
the various modes of it's doing fo are arranged 
under the general term ^direction, and mull 
be ftudied to be underftood. Infertion com- 
prifes the diverfity of manner by which leaves 
may be attached to their parent plants, each 
of which has an appropriate term, briefly and 
expreflively explained in the botanic terms 
and definitions at the beginning of the Syftem 
of Vegetables, with plates at the end of each 
volume to illuftrate them. 
I have now only to fpeak of fuch flowers 
as are commonly called double. To enter far 
into an account of them belongs rather to the 
natural hiflory of plants, than to that part of 
the fcience which ought to engage the atten- 
tion of a pupil in the beginning of his ftudies. 
It w T ill be fufficient to acquaint him with the 
unnatural varieties under which flowers ap- 
ptar, that he may not be mifled, by the monftrous 
forms 
