No. 408:] REVIEWS OF RECENT LITERATURE. 979 
no response whatever. Older larvae, Plutei and Bipennariz, became 
oriented in stronger currents and went to the kathode. Again at a 
later stage of development the electrotaxis completely disappears. 
All theoretical discussion of the results is left for a future paper. 
In view of the character of the papers here reviewed, particularly 
the first, further work along the same lines by Dr. Carlgren will be 
awaited with interest. RavuoND Print 
ZOOLOGY. 
An Introduction to Zoólogy.'— In twenty chapters the authors 
take up successively the grasshopper, the butterfly, the beetle, the 
fly, the lithobius, the spider, the crayfish, daphnia, the earthworm, 
nereis, the slug, the fresh-water clam, the starfish, the hydra, para- 
moecium, the smelt, the newt, the lizard, the English sparrow, the 
mouse. In each the type and “its allies” are described from a 
general natural-history standpoint and with an appended key to the 
chief representatives of the group. A last chapter deals briefly 
with the development of the frog’s egg. 
Then in one appendix we find the stimulating outlines of labora- 
tory work upon each of the above twenty-one forms that was proposed 
for entrance requirement at the Lawrence Scientific School, Harvard 
University. A second enumerates more than one hundred works 
and papers of reference; and a third gives a useful classification of 
the animal kingdom, with brief distinguishing characters of larger 
groups and references to the pages of this work, in which orders and 
families are mentioned. An index and glossary conclude the four 
hundred and twelve pages. 
The book is well described in the preface: * The general plan of 
this text-book is at the same time both old and new. Old, because 
it attempts to restore the old-time instruction in Natural History ; 
new, because Natural History is not to-day what it was a generation 
ago. The treatment will seem new also in contrast with modern 
text-books of zoólogy, since they are devoted primarily to compara- 
tive anatomy, a field upon which we lay little stress. . . . Itisa 
guide to the study of animals, which it is hoped may introduce many 
1 Davenport, C. B. and G. C. 7ntroduction to Zoology. A Guide to the Study 
of Animals, for the use of Secondary Schools. New York, Macmillan, 1900. 
xii 4- 412 pp., 306 figs. 
