ABA ELONGATION. 
his ‘Supplement a la flore des Pyrenées,’ p. 27, under 
the name Potamogeton bifolium, a plant which Mr. 
Bentham subsequently discovered to be nothing but a 
flowerless variety of Vicia Faba distorted by its growth 
in water.’ 
Elongation of the root.— This, as already remarked, is 
more often a variation than a malformation, and is 
usually due to the presence of water at a distance 
necessitating growth at the extremities of the root, 
or to the presence of some obstacle, such as a stone, 
to avoid which the root elongates. till it has passed the 
obstruction. Occasionally in Crocus corms some of the 
fibrils may be met with much lengthened and thickened, 
and invested with a fleshy sheath. It is not certain, 
however, that these structures are roots ; possibly, nay 
probably, they may be processes from the stem thrust 
downwards into the soil, similar to the formations 
already described in the tulip (p. 85, fig. 39). 
Elongation of the inflorescence—Under this heading it is 
necessary to consider lengthening of the common rachis 
in the case of an aggregate inflorescence, and lengthen- 
ing of the individual flower-stalks, whether they be 
solitary or portions of a multiple inflorescence. The 
two phenomena may occur together, but they are quite 
as often independent one of the other. Thus, among 
Umbellifere the umbels are occasionally met with sup- 
ported on unusually long stalks, while the pedicels of 
the individual flowers may or not be increased in 
length; so also with some of the Composites, or the 
heads of flowers of some Leguininose, Trifolium repens, 
&e. &e. 
Another illustration of the sort is that recorded by 
M. Fournier, wherein the usually umbellate inflorescence 
of Pelargonium was, through the lengthening of the 
main stalk, transformed into a raceme. Among Com- 
posites a similar change may sometimes be met with. 
'* Cat. Plant.,’ Lang., p. 113, 
