ves of certain weeds,
etc. When crushed, these tissues give off a very fetid odor, which is due
to this amine.

=Choline=, =muscarine=, and =betaine= are plant amines which are closely
related to each other and to neurine (the toxic ptomaine) in composition
and structure, as shown in the following formulas:

CH_{2}CH_{2}OH CH_{2}CHO
/ /
(CH_{3})_{3}N (CH_{3})_{3}N
\ \
OH OH

Choline Muscarine

CH_{2}CO CH=CH_{2}
/ / /
(CH_{3})_{3}N / (CH_{3})_{3}N
\ / \
O OH

Betaine Neurine

Choline and betaine are non-toxic; while muscarine and neurine are violent
poisons.

Choline and muscarine occur in certain toadstools. Betaine and choline
often occur together in the germs of many plants. Betaine is found in the
beet root and the tubers of Jerusalem artichoke. Choline occurs alone in
the seeds and fruits of many plants, sometimes as the free amine, but more
often as a constituent of lecithin (see page 141).

Phenyl derivatives of simple amines are sometimes found in
---
/ \
plants. _Hydroxyphenylethyl amine_, HO-C CH_{2}.CH_{2}.NH_{2},
\ /
---
---
/ \
found in _ergot_, and _hordeine_, HO-C CH_{2}.CH_{2}.N.(CH_{3})_{2},
\ /
---
found in barley, are examples. The former has marked medicinal properties.

There is no known physiological use for these simple amines in plants. By
some investigators, they are regarded as intermediate products in the
synthesis or decomposition of proteins; but it would seem that if this were
a normal procedure, these amines would occur in varying proportions in all
plants, under different conditions of metabol