NOTES AND LITERATURE. 
ZOÖLOGY. 
Fishes and Ascidians. — The seventh volume of the now well 
established Cambridge Natural History! contains accounts of the 
fishes, ascidians, etc., and brings the series to within three of com- 
pletion. This volume opens with a discussion of the Hemichordata 
by S. F. Harmer. Dr. Harmer’s readable account of these very 
interesting animals presents a concise description of the habits, dis- 
tribution, and anatomy of such forms as Balanoglossus, Cephalodis- 
cus, and Phoronis ; and concludes with a judicious summary of the 
evidence as to their affinities. Dr. Herdman contributes the article 
on the ascidians and amphioxus. This opens with a description of 
the anatomy of a typical ascidian, after which a general systematic 
consideration of the group is given. The chapter on amphioxus 
deals in a brief way with the habits, structure, and embryology of 
this important form. Here and there revised statements would have 
improved the text, as for instance those on the condition of the eye 
spots which were so admirably portrayed recently by Hesse. The 
commendable feature of illustrating geographical distribution by a 
chart is here marred by the fact that the signs used to represent 
Branchiostoma and Asymmetron are not printed with sufficient clear- 
ness to make them always unquestionable. 
By far the larger part of the volume is given to the fishes, the 
general account of which comes from Dr. T. W. Bridge and the 
Systematic part on the teleosts from Dr. Boulenger. Dr. Bridge's 
contribution is a safely conservative body of statement on the anat- 
omy of fishes with a reasonable amount of natural history included 
in the systematic consideration of all groups except the teleosts. 
The account in the main is excellent but is marred here and there 
by insufficiency. Thus in dealing with the ear the author treats the 
organ as an unquestionable organ of hearing, omitting all mention of 
its equilibration function, the only function thus far known for it in 
such forms as the dogfish. Both Dr. Bridge's and Dr. Boulenger's 

! The Cambridge Natural History. Vol. VII. Edited by S. F. Harmer and 
A. E. Shipley. Macmillan Co., New York, 1904. 8vo, xviii + 760 pp., 440 figs. 
339 
