934 
FACTS AND OBSERVATIONS. 
(that is, the first Friday in December), at eight o’ clock p.m. 
—The Week. 
Chemical Composition of Pus. —The British Medical 
Journal states, in a recent number (May 28, 1872), that 
Hoppe-Seyler has obtained results which are interesting in 
reference to the question of the origin of the pus-corpuscles 
and their identity with the colourless and lymph corpuscles. 
He introduced fresh crystalline lenses of the ox into the ab¬ 
dominal cavity of dogs, and analysed them after a period 
varying from one to fourteen days. As was expected, the 
lenses became infiltrated with lymph corpuscles. Glycogen 
was found in greatest abundance at the eighth day, at which 
period they contained the greatest number of contractile cor¬ 
puscles. The glycogen is due to these corpuscles. If the 
lenses were not plunged immediately into boiling water, but 
allowed to stand for some time, no glycogen was found, but 
in its place sugar. In the pus of congestion abscesses, no 
glycogen occurred. The occurrence of glycogen, therefore, 
may be taken as a means of distinguishing lymph from pus- 
corpuscles. When glycogen is found in abscesses, it will be 
found to coexist with the presence of numerous contractile 
corpuscles. Lymph corpuscles, therefore, by their transfor¬ 
mation into rigid pus corpuscles, become deprived of their 
glycogen.— The Popular Science Revieiu. 
Is there Alternation of Generations in Fungi?— 
Mr. M. C. Cook, M.A., believes that it is questionable whether 
this phenomena occurs in fungi, as Professor CErsted alleges. 
He thinks it takes place in the same plant, as in the case of 
Bunt; but he feels great difficulty in believing in this process, 
where the generations were passed in different plants, until 
confirmed by other observers. If the spores of JHcidium 
Berberidis were taken from the barberry and sown upon young 
wheat plants, and all these plants became infected with corn 
mildew ( Puecinia graminis ), to which wheat is but too prone, 
it certainly seemed premature to say that the spores of the 
JEcidium caused the Puecinia to be developed as a second 
generation; whereas it is much more probable that the germs 
of the mildew already lay dormant in the wheat, and, at most, 
the sowing and growing of the JEcidium spores only stimu¬ 
lated the mildew* to a more rapid development.— Ibid. 
The Breathing Pores of Leaves. —A good popular 
paper on this subject is that wffiich Professor T. D. Biscoe 
read before the Troy Scientific Association, and published in 
the American Natnralist } March, 1872, If, he says, the 
