64 
alone in the same light. A second method consists in suppressing 
assimilation by the use of chloroform or ether without altering the 
respiration. In the third method, two plants, of which physiological 
identity has previously been ascertained, are exposed, the one to 
ordinary air, and the other under similar conditions except that a 
concentrated solution of barium hydrate is placed in the containing 
apparatus to absorb the carbonic acid formed. Under these circum- 
stances an excess of oxygen is found in the apparatus without baryta, 
while in the apparatus containing it the carbonic acid when set free 
by hydrochloric acid is found to be in excess of that in the other 
vessel. The conclusion arrived at by the authors from these experi- 
ments is that the volume of oxygen disengaged by assimilation is 
greater than that contained in the carbonic acid decomposed- 
Four cases of poisoning through children eating snovvberries 
{Spmphoricarpiis racemosus) are recorded in the British Medical 
Journal for May i6. The symptoms produced were vomiting, purg- 
ing and delirium, followed by a serai-comatose condition. All four 
children recovered, although one suffered very severely. 
Fossil Fungus. — A certain proof of the existence of fungi at very 
remote epochs has been furnished by Messrs. B. Renault and E. E. 
Bertrand,who have found in the tissues of the nucleus of Sphcerosper- 
?num ohlongum, a plant of the coal measures, a fossil species preserved 
by silica. The mycelium of this fungus was composed of delicate 
branches, which were elongated or irregularly clustered, according to 
the dimensions of the cells by which they were enveloped. The cells 
of the hyphoe were loyu in length by 5/i in width, and appear to have 
been capable of becoming sporangia or of remaining sterile. The 
sporangia were ovoid, and 40 to 45JU in length by 20 to 25 in width, 
and swollen at the side. The fungus belonged among the Chytridi- 
acese. — Revue Scieniifiq'ue. 
Influence of Heat a72d Light upon Vegetation.— del et Terre gives 
the researches of Mr. Hellriegel upon this subject. Mr. Hellriegel 
undertook in the first place to ascertain the lowest temperature at 
which seeds are capable of germinating, and confined his experi- 
ments to 18 species of cultivated plants. The seeds, sprinkled with 
distilled water, were planted in large receptacles filled with vegetabk 
mould that were raised to constant temperatures of 48° F., 40 ''j 3^ » 
35 , and 32°, and kept there for from 35 to 60 hours. 
It was found that rye and winter wheat geminated at 32°. Barley 
and oats showed their cotyledon at 32"", but the root did not start till 
35 were reached. Indian corn required 48*^. The turnip germinated 
at ^32 , flax at 35°, the pea and clover at 35^ the bean and lupin at 
T,^ , asparagus at 35°, the carrot at 38°, and the beet at 40*"- 
The respiratory function "requires little heat, and operates even m 
the entire absence of light. Heat and light, on the contrary, are 
most favorable for the assimilation of carbonic acid and its conver- 
sion into carbon. Mr. Hellriegel attaches very little importance to 
the color of the light. 
Influence of Sunlight upon Vegetation.— M., Buysman contributes to 
a recent number of Nature an article on the influence of direct sunlight 
upon vegetation. He remarks that in the tropics plants are less de- 
