85 
vessels. The limitation of the capillary lymphatic ducts by 
proper walls is easily ascertained in this object. 
The capillary lymphatic vessels form a network, which in 
the smaller tadpoles, and in the fine border of the tail in 
larger ones, is diffused only in a single layer, but is overlaid 
on both sides with the network of blood-capillaries. 
At the margin of the vascular regions there are capillary 
lymphatic loops, of which some are remarkably narrowed ; 
but even in the interior of the border, thread-like anastomos- 
ing branches are also met with so much narrowed that their 
complete impermeability seems a matter of course. This 
supposition is rendered still more probable by the discovery 
of similar portions attached to injected ducts. In this case 
they had also in part become coloured, but were only per- 
meated as far as to the narrow part, usually furnished with a 
nucleus, where the coloration was limited to the form of a 
pointed narrow stripe. 
Csecal terminations of the lymphatic tubules also occur ; 
these issue broadly from the wall of a capillary, and usually 
terminate quickly in a point, after producing a nucleus. It 
is possible that some of these extremities may be only appa- 
rently constructed in this manner, and really represent only 
one arm of a very narrow loop, the continuity of which can- 
not be traced; but appended portions which run out. into a 
fine point, free on all sides, can hardly be regarded as any- 
thing but true caecal terminations of lateral ramifications. 
The signification of these, as also of the very narrow 
thread-like loops, must be genetic. In favour of this view is 
their similarity to the corresponding forms of the blood- 
capillaries, which are regarded and described as tubules in 
course of development. We must, however, in the author's 
opinion, know precisely what influence contractility and the 
treatment of the object may have upon the form of the finest 
vascular tubes, before we can with certainty regard all these 
vascular appendages as transition forms of new ducts. 
Origin of Minute Lymphatic Vessels. By N. Afonas- 
siew. Virchow’s Archiv, July, 1808. — N. Afonassiew, by 
employing the method of physiological injection introduced 
by his teacher (Chrzonszczewsky), has arrived at the results 
stated as follows : — The connective-tissue-corpuscles are inde- 
pendent cells, and form, through the union of their processes, 
a system of anastomosing nutritive canals, from which the 
finest lymphatic capillaries, possessing independent walls, 
arise. This view is not in accordance with the opinion 
entertained by certain anatomists of the Vienna school, who 
consider that the lymphatics arise from mere sp ices in the 
