102 GROUND FEEDS. 
or colourless outer layer of the seed coat has each cel! 
almost filled with vertical columns of mucilage grouped 
about a central cavity. Beneath, is the sub-epiderma! 
layer and then the palisade cells, filled with a dark sub- 
stance which turns red when warmed with concentrated 
solutions of hydrochloric acid and chloral hydrate 
in the proportion of one to twenty. Inside the palisade 
is an opaque, pigmented layer, while the centre of the 
seed contains oil and aleurone grains. It is here that the 
poison is located. 
TUMBLING MUSTARD—Sisymbrium altissimum L. 
Tumbling Mustard was introduced from Europe about 
1887, and is an abundant weed in the grain fields of the 
west owing to its copious seed production and its effici- 
ent manner of spreading the seeds. When ripe the plant 
breaks off and is driven by the wind, and the seeds, of 
which it is reported that there may be as many as 1,500,- 
000 on a single plant, are spread broadcast. 
The whole plant is dangerous, owing to its pungent oils. 
According to Pammel deep ulcers may be produced by it. 
The vegetative part is not palatable, but the 
seeds often find their way into feeds in 
quantity. 
Tumbling Mustard is a branching plant, two to four 
feet high. The root leaves form a rosette, but later 
shrivel and disappear. The stem leaves are 
ae oo very varied and finely dissected. The flowers 
; are pale yellow, about one-third of an inch 
across, and the slender pods are two to four inches long. 
They are borne as in other Mustards. Introduced from 
Europe, the plant has spread over the continent and is a 
very troublesome weed in the north west. 
Conditions of 
Poisoning 
