CHAP. II. 
OVULE. 
177 
ging into a seed. Its internal structure is exceedingly difficult 
to determine, either in consequence of its minuteness, or of 
the extreme delicacy of its parts, which are easily torn and 
crushed by the dissecting knife. It is doubtless owing to this 
circumstance chiefly, that the anatomy of the ovule was almost 
unknown to botanists of the last century, and that it has only 
begun to be understood within ten or twelve years, during 
which it has received ample illustration from several skilful 
observers. Brown, indeed, claims to have pointed out its real 
nature so long ago as 1814; but the brief and incomplete 
terms then used by that gentleman, in the midst of a long 
description of a single species, in the Appendix to Captain 
Flindes's Voyage, unaccompanied as they were by any ex- 
planatory remarks, prove indeed that he knew something 
of the subject, but by no means entitle him to the credit of 
having, at that time, made the world acquainted with it. The 
late Mr. Thomas Smith seems to deserve the honour of having 
first made any general remarks upon the subject: of what 
extent they exactly were is not known, as his discoveries, in 
1818j were communicated, as it would seem, in conversation 
only; but it is to be collected from Brown's statement that 
they were of a highly important nature. Since that period 
the structure of the ovule has received much attention from 
Brown, in England; Turpin and Adolphe Brongniart, in 
France ; and Treviranus, in Germany ; by all of whom the 
subject has been greatly illustrated. It is, however, to Mir- 
bel, — who, by collecting the discoveries of others, examining 
their accuracy, and combining them with numerous admirable 
observations of his own, has given a full account of the gra- 
dual development and the different modifications of the ovule, 
— that we are indebted for by far the best description of that 
important organ. His two papers read before the Academy 
of Sciences at Paris, in 1828 and 1829, are a perfect model 
of candour and patient investigation, and form the basis of 
what is here about to be recorded on the subject. I regret, 
however, that the space which can now be devoted to the 
explanation of the structure of the ovule is by no means such as 
its intricacy and interest demand. 
As the ovules are the production of the placentae, they 
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