Plate 15 



High resolution electron micrograph of several fibrils as noted in 

 cross-section of the hair cortex in the pre-keratinous zone of the human- 

 hair follicle. Compare with Plate 16. 



A fibril, F, is seen to be composed of fine filaments, / (a-filaments) 

 about 60 A wide which are embedded in a denser ground substance to 

 produce a characteristic pattern. For other forms, see Plates 16 and 17. 

 A surface of contact between two cells winds across the section and 

 may be seen in detail at C. In the intercellular spaces S much cyto- 

 plasmic debris persists. Taken from Birbeck and Mercer (1957). 



