THE SKIN AND ITS APPENDAGES 51 



having low-set tails and sharply drooping rumps. Surely the sacral 

 and coccygeal vertebra? and probably the pelvic bones are not in the 

 same position in these specimens as in those whose rumps carry out 

 almost level to the dock from the surface between the hips. And 

 there can be no doubt as to the variation in the shape, position, 

 ^elative length and size of the leg bones (Figs. 20, 21, and 22). 



I 



FIG. 22. Showing variation in length of leg bones. 



The Skin and Its Appendages. The skin of sheep varies in 

 extent, thickness and color. According to Sisson, the variation in 

 thickness is from one-half to three millimetres. In Merinos there 

 is a great expanse of skin due to numerous wrinkles and folds, and 

 as a rule their skin is thick, thus making a great weight of pelt in 

 proportion to body weight. In the English mutton breeds, be- 

 cause the skin covers the body smoothly, the weight of pelt is rela- 

 tively less. Rams have considerably thicker skins than ewes of the 

 same breed. 



In all improved breeds producing white wool except those with 



