BOTANY, 
*U 
Tournefort, and their Jifciples. The cal.yciftte diftribute 
them from the calyx, as Magnol ; and the lexualiftae .found 
their fyftem on the different (exesof plants. To this com- 
^pendions abftratf of the hiftory of botany, it may be proper 
to add, that Caefalpine, an Italian phyfician in 1583, was 
the firft fyftematic writer; and he diftributed plants into 
clafles according to the form of their feeds. Ray, from being 
fir ft a fruEliJl , became afterwards a corolijl. Boerhaave en¬ 
deavoured to combine the fyffems of Hermann, Ray, and 
Tournefort ; but as the fyftem of the latter was at one 
time very generally received, and, notwithft.mding the 
prevalence of the I.innean or fexual fyftem, has flill fome 
advocates, it may be proper to obferve, that Tournefort 
confiders plants as compofed of five parts, viz. roots, 
ftnfks, leaves, flowers, and fruit; neglecting the three 
former parts, he diftributes them into various dalles, ac¬ 
cording to the difpofttion and ftruCtureof the flower; and, 
in refolving them into genera, he takes into confideration 
both the flower and fruit. Mr. Ray, urged chiefly by 
the fliort duration of the flower, fought the characters of 
the feveral genera, not merely in the flower and fruit, but 
In the figure of the organical parts, as the leaves, (talks, 
and roots, and in their colour, fmell, take, and the out¬ 
ward furface of the whole plant. 
The fexual fyftem of botany is founded on a difcovery 
that there is in vegetables, as well as in animals, a. diftinc- 
tion of fexes. This was not wholly unknown to the an¬ 
cients; but their knowledge of it was very imperfect. It 
will be feed hereafter, that the flowers of the generality 
of vegetables are hermaphrodite, containing in themfelves 
tjie characters of both fexes; but that in the clafles mo- 
moecia and dioecia, the fexes are parted, and allotted to 
different flowers; and that in the clafs dioecia in particu¬ 
lar, the fexes are even on different plants, the male flow¬ 
ers growing all upon one plant, and the female upon ano¬ 
ther. Now this laft circumftance the ancients had ohferved : 
indeed it could hardly ef'cape their notice ; for the palm- 
tree, wliofe fruit was in efteem, being of the clafs dioecia, 
a very little obfervation was requifite to teach them, that 
in thefe trees the flowers of the male was necelfary to ri¬ 
pen the fruit of the female. It feems therefore extraordi¬ 
nary, that this difcovery fhould not have led the ancients 
to deteCt the whole procefs of nature in the propagation 
of the various fpecies of vegetables; and yet it does not 
appear, by any of their writings that are come down to 
us, that they went farther than this obvious remark upon 
the palm-tree, and feme fimilar notices concerning the tig. 
They had indeed, from what they favv in thefe plants, 
formed a notion that all others were male and female like- 
wife ; but this notion was falfe, the far greater part hav¬ 
ing hermaphrodite flowers., and ferves to convince us, that 
What they difeovered of the palm and fig was only a right 
griefs, and not founded on any knowledge of the anatomy 
of flowers, either in thofe trees, or any other. In this 
dark ftate the doCtrine of the fexes of vegetables remained, 
not only through all the ages of antiquity, but almoft to 
the end of the feventeenth century, the moderns feeing 
no more of this doCtrine than the ancients had done before 
them ; and lienee we have to this very hour in ufe, the 
falfe diftinCtions of male and female fpecies of cornns, pteony, 
cillus, and many others, which have all hermaphrodite 
flowers, the diftinCtion in thefe cafes being grounded on 
nothing more than fome difference in the habit of the two 
fpecies with which the fexes are no ways concerned. The 
honour of having firft fuggefted the true fexual diftinCtions 
in plants appears to be due to our own countryman, Sir 
Thomas Millington; from whole hints Dr. Grew, as the 
doCtor himfelf acknowledges, was led to the obfervations 
he has given on this fubjeCt, in his Anatomy of Plants. 
After this, Camerarius, Moreland, Geotfroy, Vaillant, 
Blair, Juffieu, and Bradley, purfued their enquiries and 
experiments fo far as to remove all doubt concerning thefe 
difeoveries ; and, laftly, the great Linneus founded'there¬ 
on the fyftem of botany, of which it is the objeCt of thefe 
pages principally to treat. 
The fexual hypothefis, on its firft appearance, was re* 
ceived with all that caution that becomes an enlightened 
age; and nature was traced experimentally through all her 
variations, before it was univerfally aflented to. Tourne- 
fort refufed to give it any place in his fyftem ; and Ponte- 
dera, though he had examined it, treated it as chimerical; 
but the proofs which Sir Charles Linneus has dated a- 
mongft the aphorifms of his Fundamenta Botanica, and 
farther explained and illuftrated in his Philofophia Bota¬ 
nica, are lo clear, that the birth of animals is not more 
evidently the confequence of an intercourfe between the 
fexes, than that of vegetables ; and it would be now as ri¬ 
diculous for any one, who has invefiigated the fubject, to 
doubt of the one as of the other. We fliall not attempt 
to lay all thefe proofs before t-lie reader ; but as it may be 
fatisfadory to fee fome faCt eftablifhed, that carries con¬ 
viction with it, we fliall here introduce an extraCt from 
Mr. Mylius’s letter from Berlin, which is inferted in the 
Philofuphieal TranfaCtions, vol. xlvii. concerning a re¬ 
markable experiment made on the palm-tree. “ The fex 
of plants (fays Mr. Mylius) is very well confirmed, by an 
experiment that has been made here on the palma major 
foliisJlabelliformis. There is a great tree of this kind in the 
garden of the royal academy. It has flowered and borne 
fruit thefe thirty years, but the fruit never ripened, and 
when planted it did not vegetate. The palm-tree, as you 
know, is a planta dioecia , that is, one of thofe in which 
the male and female parts of generation are upon different 
plants. We having therefore no male plants, the flowers 
of our female were never impregnated with the farina of 
the male. There is a male plant of this kind in a garden 
at Leipfic, twenty German miles from Berlin. We pro¬ 
cured from thence, m April 1749, a branch of male flow¬ 
ers, and fufpended it over our female ones; and our ex¬ 
periment fucceeded fo well, that one palm-tree produced 
more than a hundred perfectly-ripe fruit, from which we 
have already eleven yoking palm-trees.. This experiment 
was repeated laft year, and our palm-tree bore above two 
thoufand ripe fruit.” A fimilar fact may alfo be adduced 
from the cultivation of the palm or date tree in Africa, 
where dates fupply the place of corn, and afford fufte- 
nance to the people. The plantations are made in con- 
ftant fucceffion, and confifl chiefly of female plants: tliey 
flower in April and May, at which feafon the Arabs cut 
the male branches to impregnate the female : for this 
purpofe they make anincifioii in the trunk of each branch 
they wifh fhoiiid produce fruit, and place in it a bunch 
of male flowers ; without this precaution the palin-tree 
would produce only abortive fruit. In fome diftriCts the 
male branches are only fliaken over the female. This 
practice of impregnating the date-tree is very ancient: 
Pliny deferibes it with great accuracy ; and Kernpfer in¬ 
forms us how neceflary it was found by the oriental peo¬ 
ple, who live upon the produce of the palm-tree, to 
plant fome male trees among cite females, r# they hoped 
for any fruit. And lie fays it was the practice of thefe 
people, during the rage of war, to cut down all the male 
palms, that a famine may afflict their proprietors4 and 
fometimes even the inhabitants themfelves would deflroy 
the male trees w hen they dreaded an invafion, that their 
enemies might find no fuftenar.ee in the country. Thus The 
fexual hypothefis was evidently known to the ancients, 
though the diferimination of the parts fuppofed to be the 
organs of generation in vegetables, i; to be ranked among 
the difeoveries ar.d improvements of modern times. 
Of the STRUCTURE of PLANTS. 
Of the theory of vegetation, or of the growth, propa¬ 
gation, and nutriment, of vegetables, our knowledge is 
(till flight and fuperficial A clofr infpection into the ('ti nc¬ 
ture of plants affords the beft ground for reaToning on tins 
fubject, and, indeed, every thing be)und it is little better 
than mere'fancy and conjecture. On making a tranfverfe 
feclion of a tree, it appears to confift of three diltjndt parts, 
the bark, the wood, and the medulla, or pith. The bark 
c.onfifts 
