710 
Yeiv Poisoninrj. 
in the same flower, as in wheat, mustard, and most plants, nor in 
difi'erent flowers on the same plant, as in the oak and hazel, but 
in unisexual flowers borne on different plants, as in the willow. 
It is said in Hampshire that the male plants ai’e poisonous 
while the females are innocuous. 
I am not aware that any experiments have been made in 
administering to animals the foliage of plants of each sex. The 
stamens and fruits have been experimented with. A quantity 
of staminal flowers has been given sufficient to produce poison 
symptoms if they contained poison, but without such symptoms 
being produced. In the case of fruits, it has been long known 
that the ripe fleshy cup containing the seed may be eaten with- 
out injury\ John Gerarde, in his Herhall (1597), says : “When 
I was young and went to school divers of my schoolfellows and 
likewise myself did eat our fills of the berries of this tree, and 
that not once but many times.” Withering, in his British 
Plants (1796), says: “Children often eat the berries in large 
quantities without inconvenience ; ” and he adds, “ three children 
were killed by a spoonful of the green leaves.” And in our own 
day children eat the fleshy part of the fruit with impunity. 
On the other hand, when the thin crust surrounding the seed 
is broken, and the seed itself crushed and swallowed, fatal results 
have followed. It appears, then, that in the organs peculiar to 
the two sexes the stamens are innocuous while the seeds are 
poisonous. 
No difference can be detected in the stem or foliage of the 
yew at any stage of the plant. It is only after the yew has 
attained a considerable age that the sex can be determined by 
the production of the flowers. The sex of the plant cannot 
depend on the presence or absence of any special secretion in 
the plant, for though the two kinds of flowers are usually pro- 
duced on different trees, yet both kinds are not infrequently, 
though, of course, abnormally, found on the same tree. I cannot 
believe there is any foundation in fact for the asserted differ- 
ence in toxical qualities in the two sexes of the yew. It would 
be well to have the analysis of the twigs of the two kinds of 
yew, which supports Mr. Squarey’s view, made the subject 
of further investigation. 
William Carruthers. 
IV. 
Poisonous plants, such as hemlock (Conium maculatum, L.), 
nightshade (Atropa Belladonna, L.), aconite, (Aconitum Napellus, 
L.), generally owe their deleterious properties to the presence of 
