Sex-Determination in vSheep 



57 



"Each ear of a sheep as it faces you 

 presents two edges, an outer edge and 

 an inner edge, on which holes can be 

 punched in suitable positions to identify 

 the sheep. As my flock is small, and 

 simplicity is advisable, I do not find it 

 necessary to distinguish more than two 

 punch-places on the edge of the ear; 

 one as high up as possible, the other as 

 low down as possible. This gives us 

 eight well marked places where holes 

 can be punched. The shepherd is sup- 

 plied with the accompanying diagram 

 representing a sheep's head looking at 

 him, and the punch-places are marked 

 1, 2, 3, 4, 5, 6, 7, and 8, as shown. 



"Each sheep has a certain combina- 

 tion punched in the ears as an identify- 

 ing mark. By punching only one hole 

 in the proper place, we identify eight 

 sheep. By punching two holes (for 

 example, punch 1 and 2; 1 and 3; 1 and 

 4; 5 and 8; and so on) we can identify 

 28 sheep. By not limiting ourselves to 



any particular number of holes to be 

 punched, we have the possibility of 

 identifying 256 sheep. This being am- 

 ply sufficient for any purpose, I have 

 not found it necessary to distinguish 

 more than two punch-places on the edge 

 of each ear. I formerly tried three, 

 one at the top, one at the bottom and 

 one in the middle, but I found that 

 my shepherd could not handle the 

 system successfully, for it was often 

 difficult to know vvhether a hole punched 

 in the middle was intended to be above 

 or below. 



"For two years we have disting- 

 uished only two places on the edge of 

 each ear. This has turned out to be 

 perfectly satisfactory, for we can never 

 mistake the upper hole for the lower, 

 or vice versa. 



"Given eight punch-places, as shown 

 above, we can, by combinational punch- 

 ing, identify 256 sheep, as fol- 

 lows: 



Total sheep identified by hole . 



" 1 



" " 2 



" " 3 



« « u 4 



" " " 5 



" " " 6 



" " " 7 



28 

 56 

 70 

 56 

 28 



Total sheep identified by 8 holes or less 256 



■'For the purpose of identifying 

 sheep that have lost their collars (I pro- 

 vide each sheep with a leather collar 

 containing a metal plate riveted to it, 

 bearing the name of the sheep), I have 

 an index to the punch marks, and 

 against the punch-mark I record the 

 name of the sheep that bears that 

 identifying mark. When a sheep dies, 

 or is killed or sold, I scratch out the 

 name of that sheep and give its punch- 

 mark to another, so that during the 

 two years that have elapsed since the 

 adoption of the above system, I have 

 only found it necessary to use 31 com- 



binations out of a possible 256. I only 

 mark these sheep that are kept; those 

 that are to be sold are left unmarked." 

 In practice, this combination of punch 

 marks is triplicated : that is, it is applied 

 to white ewes, black ewes and rams, as 

 there could be no possible confusion by 

 having the same number used on both a 

 white ewe and a black ewe. In this 

 way, the number of positions which it 

 is necessary to punch has been kept 

 down. The use of collars on the sheep 

 has now been abandoned, as the punch 

 holes are found to meet every require- 

 ment of indentification. 



LECTURER ON EUGENICS APPOINTED 



A. Edward Hamilton of the Eugenics Record Office, Cold Spring Harbor, Long 

 Island, N. Y., has been selected to serve in an educational capacity, and his serv- 

 ices are available for lectures, on eugenics before colleges, clubs, medical societies 

 and other similar organizations. He is a graduate student of Clark University. 

 Funds for this educational extension work were given to the Eugenics Record Office 

 by Mrs. Huntington Wilson of Washington, D. C. 



