on the Hortus Malabaricus, Part IT. 173 
largely to the species of this genus, considers it as having no 
considerable affinity to any other family of plants (Enc. Meth. 
Sup. i. 575.). Mr. Brown in his valuable work on the plants of 
New Holland (i. 340.) does not differ from M. du Petit-Thouars ; 
for, although he has an order of Pandaneæ, this order consists 
of only two genera. He places this indeed next to the Aroidee, 
and allows a certain similitude between these plants; but the 
genera of the Aroideæ, which have most resemblance to the 
Pandanus, that is those in the third section, Mr. Brown has not 
placed nearest to the Pandaneæ, to. which in my opinion they 
bear a much closer affinity than they do to the Aroideæ of Jus- 
sieu. This third section of Mr. Brown constitutes the Typhe 
of Jussieu, a natural order, which in my opinion should be pre- 
served; and to this, I have no doubt, should be added the genus 
Pandanus, which bears an affinity to the Sparganium among the 
Typhe, nearly as strong as the Bambusa does to the Avena among 
the Graminee. Natural orders, in my opinion, must be founded 
on general resemblances, taking into consideration the structure 
of the whole vegetable; and I regret, that the best botanists of 
late have given too much importance to minute differences in 
the structure of parts, which, however important in the propa- 
gation of the species, are so minute and inconsiderable as to 
deserve little attention, unless accompanied by a general resem- 
blance. This is no doubt often the case; but then this general 
resemblance, of itself, is what should constitute the difference, 
whether accompanied by these minuti: or not. Besides, in the 
present state of science, it seems rash to exclude certain plants 
from a natural order, because in some of these minutiæ they 
differ from some species that have been examined; while in by 
far the greater part of the order it has not been ascertained how 
far the minute structure extends. Let it not be imagined, from 
what I have now stated, that I undervalue the minute examina- 
242 tion 
