156 REV. PROF. G. HENSLOW ON THE 
not surprising, but altogether in accordance with the principles 
of Evolution, that the organs which receive them should be able 
to interchange their functions. This possibility becomes very 
apparent in all kinds of monstrous flowers, so that nearly every 
organ, from bract to carpel, has been known to attempt to assume 
the character of every other. When, however, we search for the 
immediate causes, we are almost entirely baffled ; for we are now 
dealing with the subtle properties of life, which are at present 
both unknown and apparently unknowable, 
It is not, however, necessary to appeal to teratology; for in 
every normal flower the extremely close connection between two 
or more organs of different kinds may be seen in the fact that it 
is of the commonest occurrence for a cord to branch, and each 
branch to enter a different organ respectively. Thus, the cord 
of the petal of Primula divides tangentially, and one branch 
enters the filament, the other into the petal-lobe. Two parti- 
cular cords of the circle in Pelargonium zonale divide radially, 
and while one supplies a petal, the other forms a lateral vein iu 
asepal (xvır. 3-5; PI. XXVL). Again, a sepaline cord of Cam- 
panula medium supplies a dorsal carpellary, a staminal, and a 
petaline cord as well. 
Revnion or Corps. 
This is a phenomenon which may be regarded as the converse 
of chorisis. The process is effected in several ways :—Thus (1) a 
broken vascular cylinder may become entire by increasing the 
number of the cords by radial chorisis till they all meet; so 
that from there having been a few, say four or five only, they will 
form a completely connected cylinder. ‘This is of frequent occur- 
rence in pedicels in order to prepare for the floral members. 
Again, when a circle has thus become broken by furnishing any 
one of the whorls with its particular and definite number of cords, 
the remaining ones may close up again by radial chorisis for 
anotber whorl, and so on. 
(2) Besides the closing up of entire circles, retaining, however, 
a medulla within them, forming a vascular cylinder, individual 
cords may divide into two or more parts, aud the adjacent 
members of two distinct groups may coalesce. This is seen in 
Pelargonium, as will be described in detail hereafter. 
(3) An axial eirele may contract until the medulla vanishes ; 
