INTRODUCTION. 
1 1 
is formed of the outer Rind of the Stalk. The inner Rind and Blea, 
terminate juft within it in a kind of Button : this Button is the Recepta- 
cle, and from this the Flowers rife. In fome, as in Scabious, the outer 
part of the Blea, rifing up loofe and light, forms a kind of fpungy 
matter between the two parts ; in others, there is fcarce any thing of 
this, as in the Thrift, yet even here there is fome, and the Structure 
is the fame always. 
In refpeCt of the Footftalks of the feparate Flowers, they are in fome 
fhort, which is ufually where the Receptacle is thick, and in others 
longer, where that part is thinner ; what would otherwife make the 
thicknefs of the Receptacle running up into thefe Footftalks ; but the 
difference of longer or fhorter, is, like the former, only a mark of more 
or lefs, and can have no place in true diftinCtion. 
The Receptacle in thefe Plants is therefore of no importance and 
all that truly relates to the Footftalks of the Flowers as diftinCtive, 
is that they are always fimple and undivided : whether they are long, 
fhort, or feem wanting, is of no importance ; but if they were divided, 
it would indeed be of confequence, for it would remove the Plant out 
of the Clafs, placing it among the Umbelliferous kinds. 
It is needful that a Clafs comprehending fo large a number of Plants, 
fhould have its Orders or Subdivifions ; which we fhall take, as in 
other inftances, from differences which are obvious, in parts open to 
the eye j and dependent not on degree, but abfolutejform. 
All Aggregate Plants have the general Cup leafy in fome degree ; 
therefore no accurate diftin&ion can be made from that: but every 
Flower having its feparate Cup j and thefe differing effentially in their 
form, compofition, and divifion, and being always prefent while the 
Plant is in Flower, and very evident and open to the fight, the Cha- 
racters of our neceffary Subdivifions or Orders, may be properly taken 
from them. 
That the form, ftrudture, and compofition of the head of an Ag- 
gregate Plant, may be perfectly laid before the eye, we have repre- 
B 2 fented 
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