500 



SCIENCE 



[N. S. Vol. XLII. No. 1084 



5. Disirihuiion of Colors among the Stars of 

 N. G. 0.1647 and M. 67 : Feederick H. Seares 

 and Harlow Shapley, Mount Wilson Solar 

 Observatory, Carnegie Institution of Wash- 

 ington. 



Neither N. G. C. 1647 nor M 67 show any 

 dependence of condensation upon color which 

 can not be explained on the basis of included 

 background stars; there seems to be little, if 

 any, dependence of condensation upon magni- 

 tude; but there is a marked relation between 

 color and magnitude in N. G. C. 1647 and a 

 less pronounced relation in M. 67. 



6. On Thiele's "Phase" in Band Spectra: 

 Horace Scudder Uhler, Sloane Physical 

 Laboratory, Yale University. 



The author outlines an interpolation method 

 for determining c in the formula A = / 

 l_(n-\- c)^], which is much simpler than using 

 Thiele's complicated formula. 



7. Why Polar Bodies Do Not Develop: Edwin 

 G. Conklin, Department of Biology, Prince- 

 ton University. 



The second or internal factor in normal fer- 

 tilization is a non-difPusible substance which 

 is introduced by the spermatozoon, and it is 

 strongly suggested that this factor is the sperm 

 centrosome, a position which Boveri has long 

 maintained and which the author has hitherto 

 contested. Giant polar bodies do not develop 

 because they axe not fertilized and they are 

 not fertilized because they are generally 

 formed after a spermatozoon has entered the 

 egg and has rendered it impervious to other 

 spermatozoa. 



8. Radical Velocities of the Planetary and Ir- 

 regular Nehulce : W. W. Campbell and J. H. 

 Moore, Lick Observatory, University of 

 California. 



The fact that the gaseous nebulae have mo- 

 tions which are characteristic of the stars, and 

 their concentration in the Milky Way, indi- 

 cate that these nebulse are members of our 

 stellar system. The great velocities of the 

 nebulse in the Magellanic Clouds and other 

 considerations lead to the hypothesis that the 

 Magellanic Clouds are isolated cosmic units 

 with no apparent connection with our own 

 stellar system. E. B. Wilson 



SOME COBBELATIONS BETWEEN VEGETA- 

 TION AND SOILS, INDICATED BY 

 CENSUS STATISTICS 



Although most persons who have lived or 

 traveled extensively in the rural districts of 

 the eastern United States have probably no- 

 ticed that the proportion of evergreens in the 

 forests is usually greatest on the poorest soils, 

 and vice versa, one rarely sees any mention of 

 such a correlation in scientific, especially eco- 

 logical, literature. Most plant ecologists who 

 have taken notice of evergreens at all seem to 

 try to correlate them with climate in some 

 way; but the easily demonstrated fact that 

 two areas so close together or so similarly sit- 

 uated that they must have essentially the same 

 climate often differ greatly in their percentage 

 of evergreens shows that climate is not the 

 only factor.^ 



The making of definite correlations between 

 evergreens (or other aspects of vegetation) and 

 soils has always been difficult on account of 

 the dearth of quantitative data. No reliable 

 quantitative analysis of the vegetation of a 

 whole state has yet been made, and it would 

 take many years to do such a piece of work 

 thoroughly. To estimate the average compo- 

 sition, either physical or chemical, of the soils 

 of an area of more than a few square miles 

 would be even more difficult, for no matter 

 how many samples were collected and analyzed, 

 the judgment of the persons selecting them 

 would always introduce a " personal equation " 

 factor, unless the samples were selected whoUy 

 fortuitously, or at regular intervals (for ex- 

 ample, at the corners or centers of every sec- 

 tion of land). 



Our knowledge of the chemical composi- 

 tion of the soils of the United States is stiU 

 far from satisfactory. In Bulletins 57 and 85 

 of the U. S. Bureau of Soils are summed up 

 most of the available chemical analyses, by 

 states, and for some states there are only two 

 or three, and those probably not typical; and 

 they are not all made by the same methods. 

 In fact soil investigators are not yet agreed 

 on what method gives the best indication of 



1 In this connection see Torreya 13 : 244. 1913, 

 Sep. Mich. Acad. Sci., 15: 196-197, 1914; Ann. 

 Bep. Fla. Geol. Surv., 6: 175, 393-396, 1914. 



