September 4, 1896.] 



SCIENCE. 



319 



been made largely from human material. The 

 nerve cells of the cord and spinal ganglia, and 

 those of the cerebellum, quadigemina, thalami, 

 striata and cerebral cortex, are represented and 

 described in the order named. At the very end 

 there is given a plate from Hammarberg illus- 

 trating the size and distributions of the nerve 

 cells in six localities of the human cortex. 



In the description of the plates cell structure 

 is disregarded, because all structure is obliter- 

 ated by the silver method, and attention is there- 

 fore given alone to the shape and size of the 

 cell bodies and to the number, direction, form 

 and terminations of their branches. The de- 

 scription of the plates forms but a fraction of 

 the text, the remainder of which is a running 

 account, by Dr. Starr, of the architecture of the 

 parts named. 



This lucid and terse account is purposely dog- 

 matic and is well illustrated by the diagrams, 

 many of which are essentially new. 



Moreover, the teachings of the plates are used 

 where the silver method has enlarged our 

 notions of the architecture, and thus the plates 

 are made contributory to the more general 

 narrative. The double character of the con- 

 nections between the different cell groups in the 

 central system is one of the more important 

 points which is emphasized throughout. 



Turning to the plates themselves, which in 

 the stricter sense compose the Atlas, the question 

 is as to what is gained by the photographic repre- 

 sentation of the sections. Our impression of a 

 microscopic section is usually based on several 

 pictures offered to the eye at different depths 

 within the object, for such sections always have 

 an appreciable thickness, and only one level can 

 be brought in focus at a time. 



Photo-micrographs necessarily give a picture 

 of but one of these levels, and the rest of the 

 specimen is out of focus. The picture thereby 

 obtained is independent of the draughtsman's 

 bias and rigidly . accurate, exactly what is 

 desired. Thus, in this case the plates show 

 to perfection the cell bodies and the larger 

 branches, which were accurately focused. On 

 the other hand, the connection of the neuraxon 

 with the cell body is often lost, for it not un- 

 commonly passes out of focus just at the point 

 of junction. So, too, the mass of dendrites, 



especially where most abundant, as in Pur- 

 kinje's cells, is of necessity inadequately shown, 

 and the proper relation of the end brushes to 

 the dendrites is obscured. 



If the draughtsman is in danger of too great 

 completeness in his drawing the photo-micro- 

 graph suffers from a lack of this quality and 

 shows far less than the specimens themselves. 

 By this method therefore accuracy is gained 

 at the price of limitation. 



This criticism is intended for the benefit of 

 those who at first sight may feel a disappoint- 

 ment that the whole matter is not entirely 

 cleared up by photographic treatment. A read- 

 ing glass can be used with advantage in the 

 study of these plates, and, above all, they require 

 careful scrutiny to be appreciated. The silver 

 method is notoriously fickle, and it needs more 

 than the usual skill and perseverance to obtain 

 results by means of it; hence an atlas with good 

 plates cannot fail to be useful to many persons 

 and in many ways; and accompanied, as this one 

 is, by a most instructive text, there can be no 

 question of our indebtedness to the authors for 

 their contribution to neurology. 



H. H. Donaldson. 



Univeesity op Chicago. 



Die Insel Tenerife. Von Dr. Hans Meyer. 



Leipzig, S. Hirzel. 1896. 8vo, pp. VI., 328. 



Four maps and 33 illustrations. 



The book before us makes good its claim as a 

 scientific guide book to a most interesting re- 

 gion. Humboldt and many other well-known 

 men have given us their estimate of these 

 famous islands. The peak of Tenerife, from 

 its beautiful form and location, has been a 

 favorite theme even from the most ancient 

 times, when the virtues and charms of the 

 ' Fortunate Islands ' were proclaimed by bards 

 and philosophers. 



The work, however, like many such attempts, 

 while it is not technical enough for the scientist, 

 has a decided advantage over a mere traveller's 

 day book in that a great deal of scientific infor- 

 mation of an accurate character and in an 

 easily comprehended form is given in a pleas- 

 ant and popular style. The origin of the early 

 inhabitants as well as the fauna and flora are 

 carefully treated, and while some vexed ques- 



