76 



INITIATIVE IN EVOLUTION 



The two regions where the play of great forces comes most 

 powerfully into action during locomotion are round about the elbow- 

 joint (which we should be disposed to call the shoulder) and the 

 hip-joint, in which regions the range of extension and flexion, as 

 well as the number of muscles engaged, is much greater than at 

 any other part of the limbs. It is in the neighbourhood of these 



two regions that the most 

 characteristic of all the 

 patterns of hair are 

 found, and the names 

 given to the patterns 

 (whorls, featherings and 

 crests) in these critical 

 areas are Pectoral (Fig. 30) 

 and Inguinal (see Fig. 31 ) 

 with a third (G, H, I, 

 Fig. 31) which is called 

 Axillary, and is not con- 

 stantly present. The 

 main muscles involved 

 in Figs. 30, 31 are shown 

 in Fig. 33. The Frontal 

 (Fig. 32) is another of the 

 critical areas, indirectly 

 concerned in locomotion, 

 and will be considered 

 first. 



The Frontal pattern 

 forms the star on a 

 horse's forehead, often 

 very noticeable when the 

 hair of it is white. No 

 detailed description is 

 required if the illustra- 

 tion of it in Fig. 32 be 

 studied. It is enough to 

 point out that it lies at or very near the level of the eyes, 

 sometimes a little above and sometimes a little below this, and 

 there is occasionally a double whorl, the second lying above the 

 normal one. 



Fig. 32.4 shows the muscles of the fronto-nasal region of the 

 horse and the manner in which the skin of this central region is 

 pulled upon in divergent and opposing directions, by a long muscle, 



C 



B_- 



A._- 



30. — Front view of horse showing 

 pectoral pattern A, B, C. 



