762 THE AMERICAN NATURALIST. [Vor. XXXIV. 
view is presumably largely due to Dr. Wilson's own work, and the 
opinion now expressed in his book is that the various types of 
structure assumed for protoplasm by different schools may in reality 
represent different phases in the functional activity of.this substance. 
So thoroughgoing and complete has been the revision for the new 
edition that it will form an invaluable aid to every one interested in 
modern aspects of cytology. P. 
Intracellular Canals in Ganglion Cells. — The system of canals 
within the protoplasmic substance of ganglion cells, to which Holm- 
gren has recently called attention, has been identified by Bethe' in 
the spinal ganglion cells of the rabbit. That these canals have a 
wall of their own as contrasted with the protoplasm of the cell in 
which they lie seems doubtful They can be traced, however, 
beyond the limits of the cell, and in such regions show an undoubted 
wall; but this contains no nuclei, and hence its histological compo- 
sition is in doubt. No connection between the canals and blood 
vessels could be demonstrated, the structures in this respect differ- 
ing from the tubes discovered by Adamkiewicz. The physiologi- 
cal significance of these canals, whether they be lymph spaces or 
other such structures, is still to be ascertained. P. 
Vertebrate Anatomy. — Professor W. S. Miller? has edited and 
published under one cover four papers on vertebrate anatomy, the 
work having been done for the most part by students in his labora- 
tory. The first deals with the histology of the lung of Necturus, 
the second with this animal's vascular system, and the third with its 
brain. These three contributions are simple descriptive statements 
of the more obvious facts that they have to deal with, and are not 
far-reaching in any direction. The fourth paper takes up the ques- 
tion as to whether there are preformed natural openings on the 
lining of the body cavity of the cat, a question which is answered 
in the negative. The papers on the whole are not of a high order, 
and, in fact, it is difficult to justify the publication of the first three. 
Nor is the editorial work well attended to, as the following sentence 
! Bethe, A. Einige Bemerkungen über die “intracellularen Kanälchen "RM 
Spinalganglienzellen und die Frage der Ganglienzellenfunction, Anat. Anzeige”, 
Bd. xvii (1900), pp. 304-309. : 
? Miller, W. S. Contributions from the Anatomical Laboratory of the Univer- 
sity of Wisconsin, Bul. Univ. Wis. Science Series, vol. ii (1900), pp- 199-245 
Pls. III-XV. 
