297 
of that seen in the production of fat. The cells left after the 
fat has vanished have no membrane; and Flemming even 
asserts that the perfectly formed fat-cell has, in some cases, 
for instance in amphibia, no true membrane, the drop of fat 
being encircled by a ring of homogeneous protoplasm. 
The general results are summed up as showing that fat- 
cells are formed out of the ordinary fixed elements of con- 
nective tissue, and can, by the loss of their fat, return to the 
condition of such connective-tissue-cells again. That there 
is no special preliminary tissue, and that the name adipose 
or fatty tissue is accordingly superfluous. The ‘‘ mucous 
tissue” of Virchow has no special relation to fat; it has 
merely the characters of all embryonic connective tissue. 
The passage of fat into the fixed connective-tissue-cells is 
not to be explained by its transmission through plasmatic 
channels communicating with connective-tissue-corpuscles ; 
the existence of these channels Flemming does not admit ; 
but he proposes the hypothesis that fat circulates in, and 
passes out from, the vessels in a liquid form, and then, being 
absorbed by the connective-tissue-cells, is precipitated in their 
substauce. 
The remarkable localisation of the production of fat, he 
thinks, depends upon the dilatation of the vessels at particular 
points, and sees another evidence of this dilatation in the 
large number of migratory (extravasated) cells at these 
points. 
In an introduction, Flemming discusses the general 
structure of the connective tissue, especially in relation to the 
views of Ranvier, with which he expresses a general con- 
currence, rejecting altogether the notion of hollow corpuscles 
communicating by a system of plasmatic channels. His 
methods were principally the same as those of Ranvier; pro- 
ducing an artificial cedema of the connective tissue, with 
injections of size, mixed with silver solution, which coloured 
the tissues, and on cooling produced a mass sufficiently firm 
to cut fine sections. For tinting, he especially recommends 
the picrocarminate of ammonia solution of Ranvier, made by 
precisely neutralising an ammoniacal solution of carmine 
with a pure, concentrated, and filtered solution of picric 
acid. 
Lymphatics in connection with Cerebral Arteries.—‘ Vir- 
chow’s Archiv der Pathologischen Anatomie’ (Vol. li, p. 
568, Dec. 1870) contains an abstract of a paper, not 
yet published in full, by Dr. Golgi, of Pavia, on the 
** perivascular spaces” of His. The author holds (with 
Kolliker and others in opposition to His) that these 
