72 



SCIENCE 



[N. S. Vol. XXXI. No. 785 



the opposite side, because the depression is so 

 slight that the curvature of the moon's sur- 

 face covers the opposite wall." Or again " A 

 dessert dish five inches in diameter (without 

 the border) and less than a quarter of an 

 inch in depth has twice as deep a cavity, pro- 

 portionally, as the deepest of these depres- 

 sions." 



M. Fauth considers in detail the various 

 theories that have been advanced to account 

 for the origin of these peculiar features of the 

 lunar surface and rejects them all as unsatis- 

 factory. Yet it can not be said that he has 

 disproved the volcanic theory, although he has 

 certainly pointed out many difficulties in the 

 generally accepted idea of that theory. But 

 the theory that he advances in its place, that 

 the moon's surface is covered by a deep layer 

 of ice, will not be accepted without convincing 

 proof. 



The book is well printed and illustrated 

 and is well worth reading by those who take 

 an interest in the moon. L P. 



In Starland with a Three-inch Telescope. By 

 William Tyler Olcott. Pp. 146 with many 

 diagrams. New York, G. P. Putnam's 

 Sons. 1909. 



This is a convenient hand-book or guide for 

 the amateur astronomer. A three-inch tele- 

 scope is too small to show any planetary de- 

 tail and the owner of such an instrument is 

 practically limited to the study of the moon 

 and of a small number of the brighter double 

 stars. To a description of these objects, there- 

 fore, the book is confined. 



Only the constellations visible in the lati- 

 tude of the New England and Middle States 

 are included and these constellations are di- 

 vided into four groups, corresponding to the 

 seasons of the year in which they are visible. 

 Por each constellation a clear and simple page 

 map is given and on this map are marked the 

 positions of the interesting double stars. 

 Pacing each map is a printed page, which 

 gives the necessary details for finding and ob- 

 serving these objects. 



The moon is treated in a similar manner, 

 eight diagrams of different phases being given. 



These show the principal features only and 

 should be of great assistance to the student of 

 lunar detail. 



The book is well printed, the maps and dia- 

 grams well designed and executed, and the lit- 

 tle volume is admirably adapted to encourage 

 the study of the heavens. 



0. L. P. 



SCIENTIFIC JOURNALS AND ARTICLES 

 The Journal of Experimental Zoology, Vol. 

 VII., No. 2, contains the following papers: 

 " Wound Eeparation and Polarity in Tentacles 

 of Actinians," by Herbert W. Eand. A distal 

 cut end of a tentacle of the large actinian, 

 Condylactis, is immediately closed by mus- 

 cular contraction and remains so during a 

 slow process of structural repair which eventu- 

 ally replaces the muscular contraction. The 

 distal cut end of an excised fragment of ten- 

 tacle behaves similarly, but a proximal cut end 

 does not close. In the conspicuously different 

 behaviors of proximal and distal cut ends, and 

 in responses to tactile stimulation, the tentacle 

 shows a marked polarity which can not be 

 accounted for upon the basis of its known 

 structure. "A Biological and Oytological 

 Study of Sex Determination in Phylloxerans 

 and Aphids," by T. H. Morgan. An analysis 

 of the behavior of the sex chromosomes in 

 phylloxerans in connection with the behavior 

 of the sex chromosomes in other hemiptera 

 leads to the conclusion that these chro- 

 mosomes can not be male and female de- 

 termining as such, but that they are iden- 

 tical in all respects. Two alternative views 

 offer themselves if this analysis is correct. 

 Either sex is determined quantitatively by 

 the amount of elimination contained in the 

 fertilized egg — a view advanced by the author 

 in 1907 and since adopted by Wilson and by 

 Castle in a modified form — or else the presence 

 or absence of the sex chromosomes are asso- 

 ciated with other profound, invisible differ- 

 ences in the two classes of spermatozoa. It is 

 difiieult to decide at present between these 

 alternatives, but the facts here recorded for 

 the phylloxerans favor the interpretation that 

 the visible chromosomal differences in the two 



