Xo. 473] 



NOTES AND LITERATURE 



377 



tive, as Weismann points out (vol. 2, p. 152) ! He says, a cell changes 

 its constitution (i. e. undergoes a qualitative change) when "the pro- 

 portion of the component part and chemical combinations" is dis- 

 turbed, "when, for instance, the red pigment-granules which were 

 formerly present but scarcely visible increase so that the cell looks red. 

 If there had been no red granules present, they might have arisen 

 through the breaking up of certain other particles — of protoplasm, 

 for instance, in the course of metabolism, so that, among other sub- 

 stances, red granules of uric acid or some other red stuff were pro- 

 duced. In this case also the qualitative change would depend on an 

 increase or decrease of certain simpler molecules and atoms consti- 

 tuting the protoplasm molecule." The foregoing quotation sets forth 

 clearly Weismann' s conception of the way in which a wholly new 

 character may arise and I imagine that de Vries would accept the 

 hypothesis. They would differ only as to whether there was at first a 

 great chemical change or a slight one increasing with successive gen- 

 erations. Thus the essential difference between de Vries and Weis- 

 mann shows itself to be one of degree only. 



C. B. D. 



The Oyster.^ — A very fascinating book presenting in a thoroughly 

 scientific, yet in a readable and popular style the complete develop- 

 ment and anatomy of the oyster, the possibilities of oyster culture, 

 the cause of the decline in our oyster industry, and the remedy. 



One can hardly reaUze that since statistics have been kept (1865), 

 there have been taken from the Chesapeake Bay, upwards of four 

 hundred million bushels of oysters. " This inconceivably vast amount 

 of delicate, nutritious food has been yielded by our waters without 

 any aid from man. It is a harvest that no man has sown; a gift 

 from bounteous nature." 



This great productiveness shows how favorable this body of water 

 is for the oyster, and what might be done under judicial management 

 and culture. It is doubtful if the present areas of oyster beds (about 

 two hundred square miles) can ever regain their former prestige even 

 if they could be utilized to the best advantage by culture. The de- 

 mand has continued and will continue to outgrow the supply. The 

 area occupied by the natural beds, however, covers but a small por- 



'Brooks, William K . Thi Oijsti r. A Popular Summary of a Sckntific Study. 

 Second and rovis, ,! .nliiioii, uith introductions by Daniel C. Oilman and Ira 

 Ramsen. Baltinuwr, .h.luis li,.pkiiis Press, 1905. 12mo, 225 pp., illus. 



