November 29, 1895.] 



SCIENCE. 



741 



extended. Tke former imperfect description of 

 the male reproductive organs has been cor- 

 rected. The histology of the nervous system 

 -is more fully described and the results brought 

 up to date according to Eetzius and Lenhossek. 



The description of the development of the 

 earthworm from the egg is more fully given, 

 and a description of the internal phenomena of 

 cell-division is added. 



The process of regeneration in the earthworm 

 is incorrectly, or at least very imperfectly, de- 

 scribed. "The earthworm is not known to 

 multiply by any natural process of agamogenesis. 

 It possesses in a high degree, however, the 

 closely related power of regeneration ; for if a 

 worm be cut transversely into two pieces the 

 anterior piece will usually make good or re- 

 generate the missing portion, while the posterior 

 piece may regenerate the anterior region ' ' 

 (page 73). Earely or never will this happen in 

 the earthworm. ! If the anterior piece be suffi- 

 ciently long, i. e. , if it contains more than 24 

 segments it may then regenerate posteriorly. 

 But the corresponding posterior end will not 

 under these conditions regenerate. A shorter 

 anterior piece will not regenerate. A posterior 

 piece having lost less than 15 anterior segments 

 may regenerate and replace all or part of those 

 lost. 



Few and unimportant changes seem to have 

 been added to the description of the structure 

 and physiology of the fern. 



The brief descriptions of the unicellular forms 

 are most admirable and a most important addi- 

 tion has been made to the older volume. A 

 statement in the chapter devoted to yeast calls 

 for correction (page 188). "It was supposed 

 for a long time by Pasteur and others that yeast 

 could dispense with free oxygen in its dietary. 

 It now appears that this faculty is temporary 

 only." * * * Pasteur himself on the con- 

 trary has given the results of a most elaborate 

 series of experiments to demonstrate that yeast 

 can not permanently dispense with free oxygen 

 in its dietary. 



Chapter XVI on bacteria and Chapter XVII 

 on ' a hay infusion ' give in few words a thor- 

 oughly good summary of the part played by 

 bacteria in the world's economy. 



The first edition of the General Biology filled 



a unique place amongst our text-books and the 

 new edition fulfills all the uses of the first edi- 

 tion. It brings the latter down to date and we 

 venture to prophesy that it will meet with a 

 hearty reception. The volume is a much- 

 needed and most valuable addition to our best 

 text-books. It is well printed and illustrated, 

 and the descriptions of the authors are always 

 clear and concise. T. H. MoEGAN. 



SCIENTIFIC JOURNALS. 



AMEEICAN CHEMICAL JOURNAL, NOVEMBER. 



Jackson and Grindley contribute further 

 results of their work on the action of sodic alco- 

 holates on chloranil. They describe the meth- 

 ods of preparation, properties and reactions of 

 a number of acetals derived from substituted 

 quindnes. 



Orndorflf and Cameron find that the substance 

 formed by the action of sunlight on anthracene 

 in benzene, is dianthracene and not a paran- 

 thraceue. They obtained the substance in pure 

 condition and made a thorough crystallographic 

 study of it. Interesting points of resemblance 

 and difference were brought out by a compar- 

 ison of the measurements of the axial ratios and 

 angles. All attempts to bring about the trans- 

 formation by any other method than that made 

 use of failed. 



Hitherto all the determinatiojis of the molec- 

 ular weight of paranthracene have been made 

 by the freezing-point method. The vapor- 

 density method could not be used, as paran- 

 thracene is converted into anthracene at its 

 melting point (244°). The results obtained by 

 the freezing-point method varied greatly, and 

 were very unsatisfactory, on account of the 

 slight solubility of the substance in all the sol- 

 vents used. The authors find that, by the use 

 of the boiling-point method, using pyridine, 

 anisol and phenetol as solvents, good results 

 can be obtained. 



Campbell has prepared copper oxide contain- 

 ing a small amount of palladium, and finds that 

 the combustion of gases takes place at a lower 

 temperature when he uses this mixture than 

 when the oxygen is introduced in the form of 

 gas. 



Kastle suggests the use of the dichlor deriva- 



