DISEASES OF PLANTS. 367 
peatedly, in the Pinus Larix, met with a prolific stro- 
bilus. I have indeed seen a strobilus which pro- 
duced a sprig, on which other strobili were formed. 
In the same: manner prolific spikes are formed. in 
rich soil, in Secale cereale, Phleum pratense, Alope- 
curus pratensis, and the like. | 
3 § 343. 
A. very remarkable monstrosity in the, germen is, 
what mostly occurs in the gramina and corn, the 
Clavus. ‘The seed becomes swelled three times its 
usual size and thickness, but has no corcle. The 
cause of this affection is not yet known, but chiefly 
‘to be placed’ ina fustiness of the adducent and air 
vessels. There are two distinct species of it: 
1. The simple clavus, which 1s ofa pale violet 
colour, in its interior is whitish and mealy, without 
any smell or taste, and may be ground. along with 
the sound grain, without any bad effects on the last. 
2. The malignant clavus, which is dark | violet 
blue or blackish, and internally too has a blueish 
eray colour, a feetid smell, and a sharp pungent taste. 
Its meal is ‘tenacious, imbibes warm water only 
slowly, and has no slimy appearance when kneaded. 
The bread, however, made of it, has a violet blue 
colour. When eaten, cramps, and especially the Ra- 
phania of Cullen are produced by it. Persons should 
therefore be warned against the use of such meal. 
6 344. 
Sterilitas. We call plants sterile or barren, when 
they produce neither flowers nor fruits, All full, 
deformed, 
