Comparison of Oxygen with Helium Stars, tyc. 417 



cephalic and more variable than the men. This is in accordance with 

 the general conclusion reached in a paper on " Variation in Man and 

 Woman," * namely : 



" The lower races give ns results in sensible accordance with those 

 we have drawn from the data for ancient civilisations, namely, the 

 women are on the whole more brachycephalic and slightly more 

 variable than the men." 



(e) The younger generation is more brachycephalic and more 

 variable than its parentage. 



The whole of this difference can hardly be due to any change of 

 shape of the skull with old age, for the majority cf parents had in 

 this case not passed the prime of life. It may be due to (i) a corre- 

 lation between dolichocephaly and fertility or between dolichocephaly 

 and philogamy, or (ii) more probably to the action of natural 

 selection (results obtained, but not yet published, by the present 

 writers show a correlation between physique and cephalic index), 

 or (iii) to a greater or less admixture of white blood in the younger 

 generation. 



(/) Parents of sons are significantly less variable than parents of 

 daughters. This is in accordance with the result previously ob- 

 tained that mediocre fathers are likely to have sons,f but disagrees 

 with the result for stature — based on a far smaller probability — that 

 mediocre mothers are likely to have daughters. 



The conclusions of this paper, while appearing to the writers of 

 interest, are to be taken, in the first place, as suggestions for mnch larger 

 series of measurements and for new lines of investigation. 



" Comparison of Oxygen with the Extra Lines in the Spectra of 

 the Helium Stars, y3 Crucis, &o. ; also Summary of the 

 Spectra of Southern Stars to the Magnitude and their 

 Distribution." By Frank McClean, F.R.S. Received 

 January 12, — Read February 3, 1898. 



[Plate 6.] 



In a previous paper read before the Society on April 8, 1897, I 

 suggested that the special lines present in spectra of the first 

 division of helium stars (Type I, Divison la) might possibly be due to 

 oxygen. These stars are associated by their position and distribu- 

 tion with the gaseous nebulas, and some of the lines in their spectra 

 correspond with bright lines observed by Campbell in nebulas. The 

 suggestion from this was that these stars are in the first stage of 

 stellar development from gaseous nebulas. 



* Pearson, ' The Chances of Death.,' vol. 1, p. 370. 

 f < Phil. Trans.,' A, vol. 187, p. 274. 

 VOL. LX1I. 2 H 



