A CONTRIBUTION TO THE STUDY OF THE SCOTTISH SKULL. 349 



although it is quite possible I have ascribed a few to the wrong sex. A similar 

 statement may be made regarding those classed as females. The 90 of doubtful 

 sex I have decided to leave aside in dealing with the sexed skulls, instead of following 

 the method advocated by some craniologists, -namely, to ascribe them to the sex to 

 which they showed a preponderance of characters. In the present work I have 

 merely recorded for future use their principal measurements, and have calculated 

 some of the mean values and variations of their dimensions. 



With such a large collection of material, moreover, I can afford to set aside the 

 " doubtfuls," as the numbers left to represent the two sexes, 400 and 100 respectively, 

 are sufficiently great to make the probable error reasonably small and practically 

 to negative the influence of the inclusion of a few specimens of the wrong sex on the 

 final results. Besides, 400 is as large a number as is convenient to work with when 

 calculating the correlation coefficients by the most reliable method. 



In the Appendix I have also recorded the detailed measurements of the metopic 

 and juvenile skulls, but shall not further deal with them in the present publication. 



1. (A) The Mean Values of Dimensions and Indices of Male Skulls. 



Table I shows in four parallel columns the mean values of the dimensions of the 

 principal cranial characters given by Sir William Turner (l) for his complete Scottish 

 series and his Renfrewshire group as regards the male sex, and the corresponding 

 values in the two male groups (400 and 100) of the series of Scottish skulls under 

 examination. 



Table II, which follows, gives in three parallel columns the mean values for 

 Turner's complete female group, his female group derived from Renfrewshire, and 

 a group of 100 female skulls from our collection. The "K" series is the group of 

 100 presumably male skulls which became separated from the remainder in the 

 following way : — 



As a preliminary to a complete investigation into the characters of the skulls 

 comprising the collection, I began with a group of 100 skulls taken from the whole 

 series which, having the characters usually ascribed to the male sex fairly well 

 marked, I presumed to be, in most cases, the skulls of males. Unconsciously, in 

 making this selection, but as might have been expected, I have included in the 

 group selected an unusually large proportion of the larger skulls. This influences 

 to a marked extent, as will be seen later, the mean capacity and, to a less extent, 

 the other measurements. This group of 100 may be accepted, notwithstanding, as 

 fairly representative of the relative proportions of the male skulls, although the 

 respective mean values may be a little higher. It is to this group of 100 that I 

 have applied Klaatsch's " craniotrigonometrical " method of examination and 

 Schwalbe's measurements, and thereafter I had them all bisected in the median 

 sagittal plane to study several features only measurable after this has been done. 



