May 5, 1916] 



SCIENCE 



645 



of the " Rz " cells as derivatives of the fused 

 polar bodies and with the new light thrown on 

 the spermatogenesis of the honey bee, the re- 

 viewer has been fully, if tacitly, converted to 

 the interpretation of the origin of the sex- 

 glands from the visceral wall of the meso- 

 dermal tubes as promulgated by Wheeler and 

 Heymons and accepted by ISTelson. Of espe- 

 cial interest are the chapters on segmentation 

 and nervous system. It is rather unfortunate 

 that instead of giving a diagram of his own, 

 representing segmentation in insects, Nelson 

 reproduces in Fig. 36 a diagram from Snod- 

 grass, which can not be considered correct. 

 Nelson himself is aware of this, as may be seen 

 from his footnote on page 106. It is impor- 

 tant to mention that ISTelson describes and 

 figures the evanescent appendages of the trito- 

 cerebral or intercalary segment in in toto views 

 of the egg (Vnia, 3Br). Although the truth 

 of his statement can not be doubted, this aa 

 well as the following figures are not conclusive 

 and we regret that no figure is given of a 

 transverse section through the region of the 

 tritocerebrum as described on page 106. An- 

 other point of interest is the absence of a 

 segment between the mandibles and the max- 

 illae as described by Folsom for Anurida. The 

 reviewer has never been able to accept Folsom's 

 interpretation and finds in Nelson's description 

 a new proof against the existence of such a 

 segment. On the other hand, the rudiments 

 of the second maxillse (the future lower lip) 

 in the honey bee appear well represented in 

 Figs. X.-XIII. The rudimentary appendages 

 representing the future thoracic legs disap- 

 pear before the larva is hatched. The state- 

 ment that the abdomen consists of 12 segments 

 must be accepted as correct, but a drawing of 

 the sagittal section showing all segments is 

 wanting. A feature of great importance, espe- 

 cially for future investigators, is the table 

 showing the rate of development. The data 

 accumulated by Nelson for this are much more 

 correct and detailed than those obtained by 

 any of his predecessors. The drawings are 

 well executed and for the most part original. 

 Some of them are especially welcome, as for 

 instance Figs. 1 and 2 showing the external 



structure of the egg, Fig. 39 showing the 

 cephalic portion of the nervous system of a 

 newly hatched larva. Figs. 63 and 64 showing 

 the tracheal system and the figures reproduced 

 in the plates. 



Many readers will probably regret that no 

 account is given of oogenesis, of spermato- 

 genesis or of fertilization. To be sure, the 

 inclusion of these chapters would have in- 

 creased the size of the book as well as required 

 careful sifting of data and a great deal of 

 original, tedious reinvestigation. At the same 

 time it would be diiScult to find a more appro- 

 priate place for these chapters than in a mono- 

 graph on embryology. But it is scarcely fair 

 to criticize the author for omitting to deal 

 with a subject which does not necessarily come 

 within the scope of his work. Dr. Nelson's is 

 the first comprehensive monograph which has 

 ever been printed on the embryology of the 

 honey bee. It will be of great value both to 

 the investigator and the student and we should 

 be truly grateful to its author for having pre- 

 sented us with a work of such high standard. 

 Alexander Petrunkevitch 



SCIENTIFIC JOURNALS AND ARTICLES 



The March number (Vol. 22, No. 6) of the 

 Bulletin of tJie American Mathematical Soci- 

 ety contains : Report of the twenty-second an- 

 nual meeting of the society, by F. N. Cole; 

 Report of the winter meeting of the society at 

 Columbus, by H. E. Slaught ; " On Pierpont's 

 definition of integrals," by M. Frechet ; " Reply 

 to Professor Frechet's article," by J. Pierpont; 

 Review of Carmichael's Theory of Numbers 

 and Diophantine Analysis, by L. E. Dickson; 

 " Notes " ; and " New Publications." 



The April nmnber of the Bulletin contains : 

 " Some remarks on the historical development 

 and the future prospects of the differential 

 geometry of plane curves," by E. J. Wilczyn- 

 ski ; " A certain system of linear partial differ- 

 ential equations," by H. Bateman; "Chang- 

 ing surface to volume integrals," by E. B. 

 Wilson ; " A new method of finding the equa- 

 tion of a rational plane curve from its para- 

 metric equations," by J. E. Rowe; "The 

 physicist J. B. Porta as a geometer," by G. 



