No. 491] 



NOTES AND LITERATURE 



721 



and that may recall an adult state of an early ancestor. Moreover 

 it cannot be denied that the fossil record, meager though it is, is the 

 real record, Avhereas any scheme evolved in accordance with the eight 

 principles already named must remain, if untested by the fossil record, 

 forever hypothetical. How litde we would know of the real characters 

 and genetic relations of the reptiles or of the mammals if we limited 

 ourselves to these principles. But, it might be retorted, that granting 

 what has been said about reptiles and mannnals what light does the 

 fossil series give us on the interrelations of such groups as the animal 

 phyla, and to this question it must be admitted that no satisfactory 

 reply can be made. But is it perliaps not well to confess at once com- 

 plete ignorance of a qu(\stion which from its very nature can receiv(; 

 only such an answer as will remain forever hypothetical? The re- 

 viewer is inclined to believe that it is. 



G. II. Parker. 



Hough and Sedgwick's Physiology.^ — The volume under considera- 

 tion is a reprint of the first half of "The Human Mechanism." by 

 the same authors. T])c latter has been favorablv revicuv.l in ,!,.• 

 Xafumlht for March of this vear (p. 194). The -l>h^>i(.^.o•^ " i. 



> Hough, T. and Sedgwick. W. T. l-lriucnt s of I'hy>ioloiiy. I'.o-toii. (iinn 

 & Company, 1907. 12mo, 321 pp., illiis. S1.25. 



