264 
in the large laboratory on the first floor, 
the tables have their ends against the win- 
dows and the hoods extend along the in- 
terior walls. On this floor there are also 
four smaller rooms for research work, a 
room for photometric and spectroscopic 
work, a balance room, a room for organic 
combustions and store rooms for apparatus 
and chemicals. These last are immediately 
over the store rooms on the first floor, and 
communicate with them and with the un- 
packing room in the basement by means 
of an elevator. 
In the basement, besides the unpacking 
room, there are two large well lighted 
rooms fitted up with furnaces for work in 
assaying. There is also a room for the ap- 
paratus used in preparing distilled water. 
In the rooms on the north side of the 
basement are located the ventilating fans. 
These are driven by electric motors. In 
the system of heating and ventilating 
adopted cold air from the outside is drawn 
in by the fans and is forced over steam 
radiators and into the rooms. The warm 
air enters the rooms near the ceiling and 
the outlet flues have their openings near 
the floor. A separate system of fans, also 
driven by electricity, is placed imme- 
diately under the roof. These are con- 
nected with the hoods and with the hydro- 
gen sulphide room, and they have been so 
arranged that they can be made to draw 
air from all the hoods or they can be made 
to draw simultaneously from the hoods of 
any one laboratory. 
Epwarp H. KeEtsrr. 
DEPARTMENT OF CHEMISTRY. 
SCIENTIFIC BOOKS. 
Ueber die Natur der Centrosomen. By THEODOR 
Boveri. Zellenstudien, Heft 4. Fischer, 
Jena. 1901. Pp. 220, 8 plates, 3 text-figures. 
Probably the most remarkable series of cyto- 
logical papers yet published by a single author~ 
are the ‘Cell-Studies’ of Theodor Boveri, 
SCIENCE. 
[N. S. Vou. XIII. No. 320. 
which have placed before students of cellular 
biology not only a wealth of original discoveries, 
‘but also a model of critical analysis and lucid 
exposition that has hardly been surpassed. 
They form to-day a fine example of the value 
of intensive work in this field, for although 
they have extended over a period of nearly 
fifteen years they have been mainly devoted to 
the examination of but two objects, namely, the 
eggs of Ascaris and of the sea urchin; yet few 
works have accomplished more for the advance- 
ment of the general subject. 
The first three parts, which appeared succes- 
sively in 1887, 1888 and 1890, were inspired by 
the epoch-making res arches of Van Beneden 
on the eggs of Ascaris, and the first two were 
entirely devoted to the same object. The first 
cleared away the confusion of the earlier work 
regarding the formation of the polar bodies and 
laid the basis for most of the subsequent work 
on the reduction of the chromosomes, a subject 
which was thrown into especial prominence 
through the theoretical essays of Weismann. 
The second was a masterly study of the phe- 
nomena of fertilization and cleavage, witha full 
development of the hypotheses of the individ- 
uality of the chromosomes and of fibrillar con- 
tractility in mitosis, which exerted a far- 
reaching influence on all subsequent work in 
this field. The third placed upon a broad com- 
parative basis the epoch-making discoveries of 
himself and Van Beneden on the equivalence of 
the paternal and maternal chromosomes in fertil- 
ization (‘Van Beneden’s Law’). The fourth, 
which appears eleven years after the third, 
deals with the nature and function of the cen- 
trosome, which has become one of the most dif- 
ficult and perplexing problems of cytology. Stu- 
dents of cellular biology have eagerly awaited 
a critical discussion by Boveri of the later 
and in many respects conflicting aspects of this 
subject, in which he was one of the ablest pio- 
neers. The present work contains a detailed 
study of the centrosomes in the segmenting 
eggs of Echinus and Ascaris, a valuable critique 
of technical methods, and a critical examina- 
tion of the literature, with chapters on the 
structure and division of the centrosome in gen- 
eral, its relation to cell-division, its origin and 
physiological activity, and related questions. 
