IN FLOWERING PLANTS. 139 
It is to M. Amici as above observed that we are indebted 
for the discovery of the emission of the boyaux, and for the 
important fact of their reaching to the ovulum. The possi- 
ble existence of the boyaux was however known long previ- 
ously, for I remember seeing obvious representations of such 
among some sketches of pollen by Mr. Bauer, made, I be- 
lieve, about 1798. 
'The announcement of M. Amici with regard to the boyaux, 
was more fully worked out by M. Brongniart, who ascertain- 
ed their existence generally, and supposed that they did not 
reach the cavity of the ovarium. 
'Thus, arrested as it were, on the threshold of one of those 
discoveries, which have given additional claims to the title 
of the first botanist of this or any other age, M. Brongniart 
formed an hypothesis, on which rests the erroneous portions 
of his otherwise admirably written book. 
M. Brongniart having failed in detecting the direct com- 
munication of the tubes with the ovula, supposes that in 
all cases the fecundating matter which he takes to be the 
granules contained in the boyaux, reaches the ovula through 
the inter cellular passages of that lax tissue continuous with 
the stigma, existing in the style, and which he has shewn 
in many cases to be continued even to the ovula, the fora- 
mena of which at the period of fecundation are presented 
to it. 
But the same hypothesis has led this distinguished author 
to certain other conclusions, which will be perhaps found not 
to present much unusual anomaly. I allude particularly to his 
account of such stigmata as are covered with an epidermis, 
and especially to his figures of Nuphar. For it is at once 
obvious, that in this instance in which the boyaux are said 
to become Soude with the epidermis, that insuperable objec- 
tions exist to the passage of the granules even into the stig- 
matic tissue, since two membranes are intersposed, viz. that 
of the tube, and that of the stigma. This difficulty is 
