278 QUARTERLY CHRONICLE. 
reflections to be haunted by any anticipations of the quarter- 
day; they calmly wait till their inclinations tend in the 
direction of publication. 
Studien des Physiologischen Instituts zu Breslau. — This 
Journal, of which we have the third number before us, is 
edited by Professor Dr. Rudolf Heidenhain. It contains some 
valuable papers on human physiology and histology, as well as 
others on comparative physiology. ‘‘ Anatomical Researches 
on a Human Embryo of 28—380 Days” is the title of a paper 
by Dr. W. Waldeyer, who also contributes a memoir “ On the 
Anatomy and Physiology of the Lymphatic hearts of Rana and 
Eimys Europea.” 
Wurzburger Naturwissenschaftliche Zeitschrift.— Professor 
Kolliker has published in this journal some observations made 
by him upon the histology of the Hydrozoa and Ctenophora 
in the Firth of Clyde. In these animals he distinguishes 
three kinds of connective tissue. One forms the tentacles of 
the hydroid polyps, and all the solid tentacles of the Meduse. 
It presents the appearance of a series of cells (muscular cells of 
Keferstem) occupying the axis of the tentacle. These cells 
possess no contractility ; at least, the tentacles of the Aiginidee 
and Trachynemidz which present this structure are rigid. 
The contractile tentacles owe their contractility toa muscular 
layer situated between the cellular axis and the external epi- 
thelium. This cellular axis is only a dependence of the 
internal epithelium which lines the digestive cavity (Hy- 
droids) or the marginal canal (Meduse). It probably acts 
as an elastic organ antagonistic to the muscular layer. The 
second kind of connective tissue is a substance destitute of 
cells, which forms the umbrella of all the simple Medusz, — 
including the gelatinous substance of the natatory bells and 
covering-laminz of the Siphonophora. Sometimes this sub- 
stance is entirely homogeneous, sometimes it is traversed by 
numerous fibres very like the elastic fibres. In an Aiquorea 
these fibres are attached to a membrane capable of isolation, 
placed beneath the epithelium of the convex surface of the 
umbrella. The third form is the well-known gelatinous sub- 
stance, with disseminated cells, of the umbrella of the higher 
Medusze. Professor Kélliker agrees with Professor Virchow 
in denying the existence of these cells in Cyanea capillata. 
In connection with this subject, we may draw attention to 
the very valuable work which Professor Kélliker is now bring- 
ing out, and which every English microscopist who wishes 
to work to good effect, to the furtherance of truth and 
knowledge, should get. We mean his Icones Histiologice. 
The histology of the Protozoa has been carefully illus- 
