" 212 QUARTERLY CHRONICLE. 
foreign body, their own threads, or the surface of the water, 
and also because they are generally not able to swim freely 
through the water. 
(13) The property to bend and twist themselves, which, 
combined with rotation, seems to give them a pendulum-like 
movement, depends upon the contractility of the cells, which 
shorten a little on the concavity of the bend, and stretch a 
little on the opposite side. ‘The contractility is so great in 
Beggiatoa mirabilis that it produces vermicular waves, and 
gives peristaltic movement to the threads. 
(14) Certain Oscillarie—namely, Beggiatoa—give rise in 
water, perhaps through the decomposition of sulphuric salts, 
to free sulphuretted hydrogen. Since this class of Algze alone 
thrives in hot and strongly salted waters, it appears probable 
that the first organisms which were present in the sea of 
high temperature which covered the earth were Oscillarie, 
or rather Chroococcaceee. 
The only other article which we can notice from this num- 
ber is that of Dr. Hering on the Liver. 
The substance of this paper was communicated in parts to 
the Academy of Vienna. The author concludes that the liver 
in Reptiles, Fishes, and Birds is to be regarded as a reticu- 
larly arranged, tubular gland. The liver of mammals differs 
in this, that there is nothing whatever to be seen of an ulti- 
mate tubular structure. All the oft-repeated assertions of 
the presence of a tubular structure must be regarded as 
erroneous. Dr. Hering regards Beale’s researches, which 
tend to prove a tubular structure in the liver of the pig, as 
erroneous, in consequence of a destructive method of pre- 
paration. The view lately put forward, according to which 
the gall-vessels are regarded as a special system of capillaries, 
which, like blood-capillaries, have a special membrane form- 
ing their walls, external to which the liver-cells lie, is also, 
according to Dr. Hering’s observations on eleven different 
mammals, erroneous. The analogy between the structure of 
the liver and other secreting glands consists in this, that 
there, as here, gland-cells encompass the gland-ducts, so that 
the latter are everywhere separated from the blood-capillaries 
by interposed gland-cells. ‘The liver is distinguished from 
other glands by the relatively large layer intervening between 
blood-vessels and gland-epithelium. The paper occupies 
twenty-five pages, and enters very fully into details, a coloured 
plate accompanying it. 
Second Part.—The bulk of this number is occupied by a 
paper on epithelial and gland-cells, which is illustrated with 
seven large folding plates, and by a continuation of his re- 
