ON PLANTS IN RELATION TO ANIMALS. 303 
peculiar sulphuric odour; this is no doubt the case with all 
cruciferous plants, which contain more or less sulphur in 
their tissues. 
The resemblance of the horseradish root to that of the 
monkshood (Aconitum napellus ) has often led to fatal mistakes. 
The root of the aconite is much darker than that of horse¬ 
radish, and is more given to produce fibrillse and secondary 
rootlets.”* 
The mistake referred to, curiously enough, has been so 
much a source of mischief, that few winters pass without 
the eating of monkshood for horseradish occurring, and yet 
they are so widely different. The monkshood has a black 
outer rind, and is a soft, almost tuberous root, while the 
horseradish is of a yellowish-white colour externally, and the 
sticky root scrapes up into delicate white shavings, whereas 
scraped monkshood is pulpy, as would a potato. Horseradish 
may be employed as a stimulating poultice, and its use as a 
condiment is well known. 
2. Camelina (Gold of Pleasure) is the only native repre¬ 
sentative of the genus, if, indeed, this be not wholly an 
intruded plant. It is common to Europe and Asia, and with 
us it finds its way about farms from its introduction in flax 
seed. 
At one time it was grown to a considerable extent for the 
use of the oil which is extracted from the seeds. This oil, 
however, is not available for many purposes, as it has some 
of the stimulating character of the oil of mustard, and is, 
besides, very apt to turn rancid; its chief use is in soap¬ 
making. 
But, besides the value of the seed as an oil producer, it is 
highly extolled as food for poultry, and the cake is used for 
feeding cattle. It is, therefore, of little consequence that 
linseed so often has the gold of pleasure as one of its most 
constant weeds, as it is not found to injure the oil or the 
cake. 
3. Capsella Bursa-pastoris (Shepherd’s Purse), again 
offers a single specific representation of the genus. This, 
too, is in all probability a weed of cultivation. Be this 
as it may, there is scarcely an arable field or a garden 
that does not furnish specimens. It has no known use. Its 
strong smell and acrid flavour preclude it from being par¬ 
taken of by cattle. It is entirely devoid of any value, and, 
as it is not ornamental, we can only look upon it as a 
weed pest, to be ruthlessly cut down wherever found. 
4. Thlaspi ( Penny-cress ).— This is represented by three 
* ‘ English Botany,’ vol. i, p. 133-4. 
