428 HYPERTROPHY OF THE 
Enlargement of the perianth, &e—One or all the segments 
of the perianth may be subjected to hypertrophy ; thus, 
the utricle of Carex vulpina may frequently be observed 
to attain four or five times its usual size, the contaimed 
ovary remaining unaffected. This condition is generally 
the result of insect puncture. The growth of parasitic 
fungi will produce a similar result, as is often seen in 
the common shepherd’s purse, Thlaspi bursa pastoris, 
and other Crucifere. The perianth of Iwmex aquaticus 
has been also observed to be occasionally hypertrophied 
in conjunction with a similar condition of the pistil and 
with atrophy of the ovules. 
Moquin relates haying found flowers of Salsola Kali 
and of Chenopodium murale im which some of the seg- 
ments of the perianth were five or six times larger than 
they should be. 
The adjoining woodcut represents a singular con- 
dition of some cocoa-nuts in the Kew Museum, the 



Fic. 205.—Hypertrophy of the perianth in Cocos nucifera. 
