120 ALE§ HRDLI^KA 



The osteometric board is too well known to need special description ; 

 but for the original accessory square the writer uses a block of light 

 wood (see fig. 18), which offers certain advantages. The block is 9.5 

 cm. high and 4.5 cm. thick, while its length equals the breadth of the 

 board. 



For description of instruments used on special occasions the student 

 should consult the original sources.* 



BLANKS 



The matter of blanks in osteometry presents some difficulties on 

 account of the many distinct bones each of which requires its own 

 blank. An outline of a blank such as used for general purposes by 

 the writer will be given separately with each bone. Such blanks may 

 be made by the student himself, and their scope may be enlarged as 

 demanded by the needs of the occasion. As they are they represent 

 what invariably we should know of each of the bones. 



observations: typical bone variants in form 



Before proceeding to the measurements, attention should be given 

 to the important subject of bone variations in shape. 



Each of the long bones, and also the scapulae, first rib, etc., present 

 a variety of forms which are reducible to definite types, and t^e fre- 

 quency of these types differs from race to race. In the remainder of 

 the skeletal parts similar variations occur, but they are less classifiable. 

 The whole subject is of very considerable anthropological and phylo- 

 as well as ontogenetic importance. 



In the long bones the part that varies most in form is the shaft;' 

 in the scapula it is in the contour of the bone. Bones of less conse- 

 quence will be considered on other occasions. 



' Besides the Memoirs of Broca and the textbooks of Topinard and Martin, see: 

 Emmons (A. B.) — A study in the variations of the female pelvis. Biometrica, 1913, 

 rX, 34-57. Garson (G.)— Pelvimetry. J. Anal. & Physiol., 1882, XVI, 106-134. 

 Frassetto (F.) — Lezioni di anthropologia, 1911-1913. Hepburn (D.) — A new osteo- 

 metric board. J. Anal. & Physiol., 1899, XXXIV, 111. Matthews (W.)— An 

 apparatus for determining the angle of torsion of the humerus. J. Anat. & Physiol., 

 1887, XXI, 536-8. Russell (F.) — A new instrument for measuring torsion. Am. 

 Nat., 1901, XXV, 299. 



* For original reports on this subject see Hrdlicka (AleS) — Study of the normal 

 tibia. Am. Anlhrop. 1898, XI, 307-312; Proc. Ass. Am. Anal., 11 Sess., Wash. 1899, 

 61-66. — A further contribution to the study of the tibia, relative to its shapes. Proc. 

 Ass. Am. Anal., XII & XIII Ses. Wash. 1900, 12-13.— Typical forms of shaft of 

 long bones. Proc. Ass. Am. A?ial., XIV Sess., Wash. 1901, 55-60. Also Bull. 62, 

 Bur. Am. Ethnol., Wash. 1916. Consult also: Manouvrier (L.) — La platycn^mie 



