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84 
contractility.” From the foregoing the following corollaries 
are deducible : — The analogy between pus-cells and colourless 
blood-cells ; the impossibility of distinguishing the two in 
the blood ; the morphological agreement between a recent 
exudation (as in pneumonia or pleuritis) and the product of 
purulent softening of the same, on microscopical examina- 
tion, &c. — Journal of Anatomy, November, 1868. 
New Experiments on the Genesis of Leucocytes. By 
Dr. Onimus. Robin’s Journal, November and December, 
1868. 
On Capillary Vascular Systems in the Gasteropoda. 
By Professor C. Wedl. Anzeige der Akad. der Wiss. in 
Wien, July 23rd, 1868, p. 179. — The theory proposed by 
Milne-Edwards, that in the Mollusca the arterial and venous 
systems are not united by a capillary system, but that a 
system of lacunae destitute of proper walls intervenes be- 
tween them, is not confirmed in the Gasteropoda investi- 
gated by the author. In Helix, Limax, Turbo, Limnceus, 
and Murex he has ascertained the existence of closed capil- 
lary systems, with proper walls and characteristic of the 
different organs; these may be displayed by injection either 
from the arterial or the venous side. The existence of a 
lacunar system must be denied even in the respiratory 
organs. Nor could he convince himself that the vascular 
system is open either towards the cavity of the body or the 
outer surface. Hence the theory of the imperfect circula- 
tion of the blood in the Gasteropoda is, at least, not of 
universal application. 
These observations of Professor Wedl’s are of greater 
importance when considered in connection with Mr. Charles 
Kobertson’s recent account of a similar condition of things 
in Helix pomatia. Mr. Robertson’s observations are re- 
ported by him at p. 148 of Vol. VII of our Journal. 
On the Lymphatic Vessels in the Tail of the Young of Batra- 
chia. By C. Langer. Anzeige der Akad. der Wiss. in Wien, 
July 23, 1868. Successful injections of this system of vessels 
facilitated the detection of many uninjected vessels, which 
could be traced from the ends of the injected portions of the 
tubes for a long distance in the tissue of the border of the tail. 
They not only permitted the arrangement of the whole system, 
but also the structure, connection and termination of the 
individual vessels to be investigated. 
The author found that they have sharply marked, even 
outlines, without any indentations. Their appearance, as 
regards the constitution of the walls and the form of the 
nuclei, was hardly different from that of the fine blood- 
