JuLy 23, 1897]. 
The cerebral light is located in those higher cen- 
ters of the brain which are connected with vis- 
ual memories and imaginations. While watch- 
ing the cerebral figures I find that my visual 
memories or phantastic figures appear in the 
midst of the cerebral light and frequently can- 
not be distinguished from them. The close con- 
nection of these cerebral figures with the con- 
tents of dreams has been repeatedly noticed by 
Johannes Muller and a series of later observers. 
There is also the possibility that the hallucina- 
tory visions produced by hashish, mescal and 
other drugs may be simply modifications of this 
cerebral light. 
E. W. SCRIPTURE. 
YALE UNIVERSITY, May 21, 1897. 
SCIENTIFIC LITERATURE. 
Grundriss der Entwickelungsgeschichte des 
Menschen und der Stéiugethiere yon Dr. MED. 
OscAR SCHULTZE. Bearbeitet unter Zugrund- 
elegung der 2. Auflage des Grundrisses 
der Entwickelungsgeschichte von A. Kolliker. 
Leipzig, Engelmann. 1897. 8yvo. Pp. vii+ 
468. 
Kolliker’s well known manual has been so 
thoroughly reworked by Professor Schultze 
that it is essentially a new work. In Kolliker’s 
volume the embryology of the chick furnished 
many of the descriptions and illustrations. 
Schultze has omitted the chick altogether, con- 
fining himself strictly to mammalian develop- 
ment, and has added a comprehensive though 
very condensed account of the fetal mem- 
branes and placenta in the chief groups of 
mammals. Many new and admirable figures 
have been added, of which a considerable 
majority are original and taken from the 
author’s own preparations. 
It is exceedingly difficult to characterize 
Professor Schultze’s text-book fairly, for it 
combines superior merits with conspicuous and 
singular defects. It is utterly inadequate as a 
presentation of contemporary embryology, for 
it systematically neglects the morphological, 
phylogenetic and mechanical aspects of embry- 
ology, and consequently reads almost like an 
old-fashioned descriptive anatomy. An embry- 
ological writer might be excused for avoiding 
phylogenetic and mechanical themes, but the 
- SCIENCE. 
139 
neglect of morphological considerations makes 
full success in writing a text-book an impossi- 
bility. To illustrate these criticisms it suffices 
to examine the account of the nervous system ; 
in the development of this the history of the 
neuro blasts and of the division of the medullary 
tube into dorsal and ventral zones are the 
fundamental facts morphologically, but our 
author barely describes the neuroblasts, does 
not figure them at all, and makes no allusion 
to the two zones, which should form the basis 
of the whole account, for without understanding 
these zones no student can master even the 
rudiments of our present knowledge of the 
brain and spinal cord. Again, the epidermisis 
equally maltreated, for the history of the 
epitrichium is incorrect, and no mention what- 
ever is made of the fact that the nails are modi- 
fications of the stratum lucidum. Erroneous 
are also the accounts of the development of the 
glands in the stomach, which do not develop 
in the same way as those of the intestine ; mis- 
leading is the history given of the supra-renals, 
for the so-called medulla of the organ in the 
human species is not derived from the sympa- 
thetic Anlage. There are mistakes in the illus- 
trations: in Figs. 194 and 195 the ‘ Zwischen- 
hirn’ (Diencephalon) is correctly designated, 
but in Figs. 217 and 263 the same division of 
the brain is called ‘Mittelhirn’ (Mesence- 
phalon) ; in Fig. 327 the left side of the heart is 
called ‘rechte Kammer’ and the right side 
‘linke Kammer,’ while the great vein is labeled 
‘Sympathicus!’ Of the index complaint must 
be made : one searches it in vain for Hirnblasen, 
Nerven, Thyroidea and other headings. 
In spite of these criticisms, which indicate 
that the usefulness of the book is severely . 
limited, the manual remains one of many 
merits and of great value. The author is fe- 
licitous in his combination of brevity and clear- 
ness, and in avoiding cumbrous accumulations 
of details. The faulty illustrations are excep- 
tions; very good ones indeed are the rule, good 
both in selection and execution. In printing 
them the publishers have sustained their high 
reputation in this regard. The author has 
studied at first hand, and is thereby enabled to 
make his descriptions fresh, vivid and interest- 
ing, and if he had included in his point of view 
