110 



SCIENCE. 



[N. S. Vol. XII. No. 290. 



a centrosome to the egg cell, whicli before the 

 entrance of the spermatozoon lacked a centro 

 some and was, therefore, incapable of division. 

 Since then a large number of investigators have 

 devoted attention to this subject with more or 

 less conflicting results. In the first edition of 

 his book on the Cell, Professor Wilson took a 

 very positive stand in favor of the hypothesis 

 of Van Beneden and Boveri ; in the present 

 edition he takes the much safer ground that the 

 problem is still an open and unsolved one. As 

 to the origin of the cleavage centrosomes he 

 suggests (p. 230 et passim) that Boveri's hypo- 

 thesis may still be maintained in a modified 

 form if we assume that the sperm centrosome 

 gives rise indirectly, through chemical stimuli, 

 to the cleavage centrosomes. 



Other important changes are found in the 

 treatment of the structure of protoplasm, the 

 mechanics of mitosis, and chromatic reduction, 

 while minor alterations are found on almost 

 every page. There are about 100 additional 

 pages and more than 50 new figures, while sev- 

 eral old figures have been redrawn and im- 

 proved. 



On the whole, the author's temper is much 

 more cautious and judicial than in the first edi- 

 tion, while at the same time there is no loss of 

 that enthusiasm which is the peculiar charm of 

 his writing. The few erroneous statements of 

 the first edition have been entirely rectified, 

 and few, if any, new ones have crept in. 

 Strange to say, however, the typographical 

 errors have increased, though they are still few 

 and for the most part unimportant. Too much 

 praise cannot be given to the mechanical exe- 

 cution of the work. The illustrations are of 

 the highest type of excellence ; in fact it is no 

 exaggeration to say that many of the figures 

 are clearer and better than the originals 

 (usually lithographs) from which they were 

 taken. 



The book mark of the Columbia Biological 

 Series has been changed from a mitotic figure in 

 the metaphase to one in the anaphase, which 

 fittingly symbolizes the passing of this work 

 from a first to a second edition. Although one 

 of the latest books in this field, this is the first 

 general work on cytology to pass through a 

 second edition. May it see still other editions. 



telophases and yet other cycles of development, 

 in the future ! 



Edwin G. Conklin. 

 University of Pennsylvania. 



North American Forests and Forestry, Their Re- 

 lations to the National Life of the American 

 People. By Ernest Bruncken, Secretary 

 of the late Wisconsin State Forestry Commis- 

 sion. New York and London, G. P. Put- 

 nam's Sons. 1900. Pp. vi+266. 

 This work, which appeared early in the year, 

 is a timely contribution to the much needed 

 literature of forestry in North America. We 

 have been so earnestlj' engaged in ridding the 

 ground of the covering of trees which prevented 

 us from ' planting corn to feed to hogs, to sell 

 for money, to buy more land, to plant more 

 corn, to feed more hogs,' etc., etc., that we 

 have overlooked the fact that a forest is often 

 the best crop which a given area can produce. 

 With the disappearance of the great forest 

 tracts we are learning the hard lesson that we 

 have ' wasted our substance in riotous living,' 

 and as the thoughtless prodigal of old finally 

 ' came to himself when he had spent all, so we 

 are beginning to have different notions as to 

 the value and importance of the heritage of 

 trees which we so thoughtlessly wasted. This 

 book is itself a result of this changed feeling. 

 It is an attempt to treat the forest problems of 

 the country as of such importance as to demand 

 our most thoughtful consideration. 



Some idea of the scope of the book may be 

 obtained from the titles of a few of the chapters: 

 The North American Forest, The Forest and 

 Man, The Forest Industries, Destruction and 

 Deterioration, Forestry and Government ; For- 

 estry and Taxation ; Reform in Forestry Meth- 

 ods, Forestry as a Profession, etc. In the 

 treatment of these topics the author discusses 

 each with liberality, and is not given to urging 

 his particular theory upon the reader's atten- 

 tion. In fact the book is very largely a calm 

 discussion of forestry questions, and it is singu- 

 larly free from long statements of the author's 

 particular theories as to the proper solution of 

 the problems in hand. 



It should have a large sale throughout the 

 country and should be found in every public 



