238 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 10 



first 3 months the cephalic index constantly increases, the prevalent 

 skull form during this period being mesocephalic. From the fourth to 

 the tenth month the index varies slightly, brachycephaly prevailing. 

 The index decreases during the tenth month, as a result of parturition. 



The fluctuation of cephalic index in different embryos may vary 

 greatly in point of time. This is true with twins in the majority of 

 cases. 



In no instance does head breadth exceed head length. The curves 

 of the absolute length and breadth are very similar to the curves of 

 their absolute growth, by month. Head length increases more than 

 head breadth up to and including the fifth month, which shows the 

 greatest difiference in increase of any month. 



A definite periodicity governs the absolute increase of length and 

 breadth of head, as well as length of body and leg. Up to the fifth 

 month there is successively greater increase; from the sixth to the 

 ninth month the increase fluctuates; the pre-parturient period is 

 characterized by a sharp rise. 



Sex dimorphism is clearly expressed. The cephalic index of girls 

 in utero is lower than that of boys except during the last 2 months, 

 when that of girls becomes greater. In general, newborn girls are more 

 brachycephalic than boys. During the first half of uterine develop- 

 ment girls surpass boys in their growth. The growth of all their 

 dimensions is more evenly distributed between the two halves of 

 uterine life than is that of boys, whose growth is shifted more to the 

 second half. 



A STUDY OF BLOOD GROUPS IN THE CAUCASUS ^s 



Anthropological study of blood groups in Georgia was begun in 

 1925 by the Hematological Department of the Georgian Bacterio- 

 logical Institute. The blood groups of all patients in the Hemato- 

 logical and W'assermann Departments were recorded, together with 

 data regarding sex, age, and nationality. 



One thousand measurements disclosed tentatively the prevalence 

 of Group I (O) among the Georgians and of Group II (A) among 

 the Armenians. The extreme western and eastern groups represented 

 the maximum range of brachycephaly and dark pigmentation. The 

 highest degree of both was found in the east, the lowest in the west. 



^^ Semenovskaia, E. M., Izuchenie grup krovi narodov Kavkaza [Study of 

 blood groups in the Caucasus]. Sovetskaia Etnografiia, Nos. 4-5, pp. 213-215, 

 1936. 



