742 Mr. Brown on the Organs and Mode of 
does not however extend to their gradual increase and progress, 
both of which may be absolutely ascertained. 
In Bonatea they are, in the first stage of their production, 
confined to the stigma, with the proper tissue of which they are 
-more or less mixed. Soon after they may be found on the an- 
terior protected surface of the style, at first in small numbers ; 
but gradually increasing, they form a mucous cord of consider- 
able size, in which very few or none of the utriculi of the stigma 
are observable. This cord, which is originally limited to the 
style, begins, though sometimes not until several days have 
elapsed, to appear in the cavity of the ovarium, where it divides 
and subdivides in the manner I have described in my paper, its 
descent being gradual until the cords nearly equal the length 
of the placenta, to which they are parallel and approximated. 
That these cords are not in any degree derived from those 
portions of the walls of the cavity of the ovarium, to which they 
are closely applied, and which I have termed the conducting 
surfaces, is manifest from the identity in state of those sur- 
faces before and after the production of the cords. 
In Bonatea the first evidence of the action of the pollen con- 
sists in the withering of the stigma; a similar decay of the 
greater part of the style soon follows, and the enlargement of 
the ovarium generally begins before the withering of the style 
is completed. When the enlargement of the ovarium is consi- 
derable, and the mucous cords are carefully formed in its cavity, 
a corresponding enlargement of the ovula takes place, and the 
nucleus becomes first visible. 
I have no satisfactory observations in Bonatea respecting any 
tubes going off from these cords and mixing with the ovula ; 
but in Orchis Morio I have repeatedly and very clearly observed 
them scattered in every part of the surface of the placenta, and 
in not a few cases have been able to trace them into the aper- 
: | ture 
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