JuNE 7, 1901.] 
by Charles Schuchert, in which he describes 
the fauna of Saint Helena as from the Helder- 
burg and the middle Devonic ages. 
SOCIETIES AND ACADEMIES. 
BIOLOGICAL SOCIETY OF WASHINGTON. 
THE 340th meeting was held on Saturday 
evening, May 4th. 
T. H. Kearney presented a paper on ‘ Loeb’s 
Tuvestigations into the Action of Ions upon 
Animal Structures, as supplemented by Studies 
with Seedling Plants,’ quoting from Loeb’s 
published papers at some length, special stress 
being laid upon their value as illustrating the 
theory of the réle of ion-proteid compounds in 
vital phenomena. In experiments with animals 
it was the action of mixed solutions of two or 
more salts, as compared with that of each salt 
in a pure solution, which led to the develop- 
ment of this theory. The result of numerous 
experiments with seedling plants, as to the 
limit of concentration of solution which per- 
mitted the maintenance of vitality, agreed in 
many important points with the results ob- 
tained by Loeb in experiments with animals. 
In both cases salt solution was found to be 
highly toxic, while the addition of a second 
salt in many cases largely neutralized this 
poisonous effect and notably increased the de- 
gree of concentration of the more toxic salt in 
which root tips could survive during a twenty- 
four hours’ culture. 
Experiments were made with salts of mag- 
nesium (sulphate, chloride), of sodium (car- 
bonate, sulphate, chloride and bicarbonate) and 
calcium chloride, all of which are important 
components of ‘alkali’ soils in the western 
United States. In pure solution they proved 
toxic in the order named, the limit of endurance 
for magnesium sulphate being approximately a 
aso DOrmal solution, that of calcium chloride a 
i normal. Mixtures were made of equal vol- 
umes of definite concentration of each two of 
these readily soluble salts, and of each of them 
with the comparatively insoluble magnesium 
carbonate, calcium carbonate and calcium sul- 
phate, which are likewise abundant in the 
alkali soils. 
In several cases addition of a sodium to a 
SCIENCE. 
909 
magnesium salt considerably raised the limit 
of concentration of the latter endurable by the 
roots of the white lupine (Lupinus albus), but 
the most striking results were obtained by the 
addition of calcium, either as chloride or sul- 
phate, to magnesium and sodium salt solutions. 
Calcium sulphate, added in simple excess of 
the powdered salt, proved extraordinarily effi- 
cacious in neutralizing the toxic effects of other 
bases, increasing the maximum endurable con- 
centration for sodium sulphate from zj5 to z 
normal, and for magnesium sulphate from yoo to 
2 normal. 
In a 2 or 2 pure solution of magnesium sul- 
phate the root cells were strongly plasmolyzed, 
while in a corresponding solution plus an excess 
of calcium sulphate no trace of the plasmolyzing 
action could be detected. The effect of calcium 
sulphate upon the corresponding chlorides was 
much less marked. Hence, while in some cases 
the effects of mixtures could be ascribed to the 
kations (basic radicle) alone, in others it seems 
clear that the anions are also able to make 
their influence felt. Hydroxyl ions, dissociated 
in very dilute solutions of sodium carbonate 
(Na,CO,), and sodium bicarbonate (NaHCO,), 
markedly stimulated the growth of the roots, 
just as Loeb found them to stimulate the 
gastrocnemius of frogs, to absorption of water 
from, and rhythmical contraction in, a sodium- 
chloride solution. 
The results of this investigation, which was 
undertaken at the request of the Chief of the 
Bureau of Soils of the Departmeut of Agricul- 
ture, are to be described in a forthcoming 
bulletin of the Division of Vegetable Pathology 
ofthat Department. They are believed to have 
considerable economic significance, apart from 
their bearing upon the question of the influence 
of ions upon organisms. 
Under the title ‘A Kinetic Theory of Eyolu- 
tion,’ Mr. O. F. Cook suggested, on the basis 
of studies in the Diplopoda and other groups, 
that evolution be interpreted as a kinetic phe- 
nomenon or process of gradual and spontaneous 
accumulation of variation instead of a reaction 
to external conditions. It was also held that 
the differentiation of species is a process quite 
distinct from evolutionary progress, and that 
selection and isolation may conduce to the 
