IN FLOWERING PLANTS. 2k 
- The boyaux pass down, imbedded in the lax tissue of the 
stigmatic canal. ey terminate at various points: a very 
few, and often only one, reaching the funicle, to which they 
appear to be guided by the conducting tissue. They are here 
turned from their original course, passing off round the funi- 
cle, towards the cap-shaped process. 
Along this they descend in a generally tortuous manner, 
and one or two become engaged in the exostome within 
which they pass; tracing them (or it, as the case may be) 
further, we find them engaged in, and passing along the bot- 
tle-shaped neck of the secundine, until they reach the nu- 
cleus, to the loose cellular apex of which they become appli- 
ed apparently rather firmly.* Beyond this I have ascertained 
nothing. 
The boyaux terminate in a cul de sac, at least I have not 
been able to ascertain the existence of any opening. PL 56, 
fig. M.3. c. Ihave never traced more than two into the open- 
ing of one ovule. In one case the tube was branched, both 
terminations having reached the nucleus. PŁ. 56, fig. M. 2, 
3. I observed no circulation either in the grains of pollen or 
in their tubes. 
The tubes appear occasionally to be broken up, if I may so. 
express it, before they reach the cap, or reflected funicular 
portion of the conducting membrane. This, when such is the 
case, appears to contain, or rather to be scattered over with 
grumous granular matter, which still passes off to, and appears 
to penetrate the apex of the secundine, and has precisely the 
appearance of the fovilla of pollen, when this has burst by 
the action of water. See pl. 56, fig. M. 4. c. The absence, or 
disappearance of the tubes is very curious, particularly as 
impregnation still takes place effectually. I may observe, 
that while examining these ovula during the rains, I only in 
one instance traced the tubes to the ovula. In every other, 
and I examined some hundreds, nothing of the sort was 
* I have traced them so far in a Crotalaria, in which they end in cul de sacs, 
ane are applied to the apex of the nucleus. In one instance two new and small- 
T tubes or cells had become applied to the a end of the boyaux!! Both 
Ss. cells contained granules. 
