头发分叉是因为毛干的表层(或角质层)已经损坏。

Hair furcation because the surface layer (or periostracum) of hair stem has been already damaged.

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结果：动物表皮有一层角化过度的角质层，毛干消失，毛球结构不正常，毛囊内为一些角化物质，有的变为空囊腔。

Results: There is a excessively keratinized layer in the animal epidermis, loss of hair shaft, abnormal structure of hair bulbs.

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