— 82 — 
ring, proved to be typical paralysing toxins, with which a spasm- 
producing action could not be observed. The activity of the isoximes 
increases with the size of the ring, and also with the entry of a methyl- 
group. Specially powerful is the action of bodies with propyl-groups, 
particularly of those in which (as in isofenchone oxime) the propyl 
group is not attached to the ring, but inserted in it. Bihydrolaevo- 
menthone oxime and Isevomenthone isoxime have a paralysing effect 
in frogs, but in mice they act as spasm-toxins without producing 
symptoms of paralysis. A practical application of these isoximes by 
way of collapse-remedies can scarcely be taken into consideration. 
These compounds may, however, possibly be employed in cases where 
it is intended to obtain a general, more powerful respiration. 
Phyto-physiological notes. 
Carl Detto in his thesis^) deals with the importance of the 
essential oils in Xerophytes (plants of a very dry habitat). The author 
considers that the researches of various investigators have adequately 
confirmed the supposition that the essential oils of the internal gland 
organs of numerous families of plants {Simaruhaceae , Canellaceae, 
PiperaceaCj Lauraceae, etc., with secretion cells — Hypericaceae, Rutaceae, 
Myriaceae, etc. with secretion openings; Umbelliferae , Araliaceae, Anacar- 
diaceacy Burseraceae, etc. with ducts) form a means of protection against 
animal enemies. On the other hand, he occupies himself in detail 
with the significance of those essential oils which are formed in a 
readily volatilisable ^tate in the external glands of organs, especially 
of the leaves. Here Detto opposes the view represented more par- 
ticularly by Tyndall, that to the essential oils belongs the task o^ 
reducing the loss by perspiration, — on the one hand by the powerfu. 
absorption-capacity of their vapours for heat, and on the other hand 
by the formation of vapour itself, as a heat-abstracting process which 
diminishes the rapidity with which water evaporates. 
On the strength of his study of the literature on the subject, and 
in consequence of numerous experiments made by himself from a 
phy to -geographical, anatomical, physical, and physiological point of 
view, the author comes to the conclusion that the absorption-capacity 
of the essential oils for heat which Tyndall had laid down, is of no 
importance whatever for the plant, and that a reduction of the 
perspiration by the action of the oil-vapours up to an oecologically 
active level, could only take place with simultaneous injury to the 
perspiring organs. On the contrary, the exogenous essential oils, apart 
from the odorous substances of the blossom, should also be considered 
as protective agents against insects, snails, grazing cattle, and other 
^) Carl Detto, Thesis, Jena 1903. 
