450 SOME NEW BOOKS [DECEMBER 
OUR PLAY. 
Die Spiele der Menschen. By Kari Groos, Professor of Philosophy in 
Basel. Pp. 538. Jena: Gustav Fischer, 1899. Price 10 marks. 
Two or three years ago Professor Groos rather startled us by his book “ Die 
Spiele der Thiere,” in which he showed that play was one of the most serious 
things in the world. This book was translated last year by Mrs. Baldwin, and 
published, with a preface and an appendix by Professor J. Mark Baldwin, under 
the title “The Play of Animals: a Study of Animal Life and Instinct.” The 
author’s thesis has thus become familiar. Play is not mere by-play, but a 
matter of serious moment; it is the expression of an instinct developed by 
natural selection, and justified (1) because the playful young animal can rehearse 
without responsibilities, and practise for its future lfe without serious con- 
sequences, play being really the young form of work; and (2) because the 
young animal is able in play to learn many lessons which would otherwise have 
to be inherited as special instincts, thus lessening the burden of inheritance, 
and putting a premium on intelligence. To which may be added that the play- 
period affords elbow-room for new departures—an ‘ A bdnderungsspielraum ”>— 
before natural selection begins to operate with its usual sternness. 
In the volume now before us Professor Groos applies his ‘ practice theory ” 
of play to the games of children and men, and on the whole seems to succeed 
in corroborating it, though the case does not seem to us quite so clear as it was 
when animals alone were dealt with. The first section deals with playful experi- 
menting—sensory, motor, intellectual, and emotional. The second section dis- 
cusses combative play, love play, imitative play, and social play. Then follows 
a general consideration of the theory of play, looked at from six points of view— 
physiological, biological, psychological, aesthetic, sociological, and educational. 
We do not know whether to admire most the author’s erudition, or his 
vivacity, or his intellectual perspective. The result is certainly a notable con- 
tribution to the theory and art of life. It invests the familiar adage, ‘‘ All 
work and no play makes Jack a dull boy,” with a profoundness of solemn 
meaning. 
It is to be hoped that this volume will also be translated by Mrs. Baldwin, 
who dealt so successfully with the first, for it is a book that ought to have the 
widest possible circulation, not merely because it is a thorough vindication of 
what we may call the Darwinian theory of play, but also for its practical sug- 
gestiveness to parent and teacher, physician and artist. 
MATSCHIE’S CATALOGUE OF FRUIT-BATS. 
Die Fledermiuse der Berliner Museums fiir Naturkunde: 1 Lieferung, Die 
Megachiroptera. By P. MATSCHIE. 8vo, pp. vili.+ 103, pls. 14. 
Berlin: George Reimer, 1899. Price 24 marks. ' 
The British Museum “Catalogue of Chiroptera,” by the late Dr. Dobson, 
having been published so far back as 1878, has long been completely out of 
date ; and naturalists should therefore welcome Dr. Matschie’s new descriptive 
synopsis, of which the first instalment is before us. It appears that the late 
Professor Carl Peters, Director of the Berlin Museum from 1857 to 1883, 
contemplated the publication of a monograph of the Bats, for which were 
prepared no less than 75 lithographic plates, executed by the well-known 
artists F. Wagner and G. Miitzel. These plates remained in the hands of Herr 
G. Reimer, the publisher,’after the death of Professor Peters, but no accom- 
panying MS. was found among the effects of the latter. This being so, 
Dr. Matschie determined to write the text for a descriptive synopsis of the 
