274 



MANUAL OF HISTOLOGY. 



PIG. 118. Horizontal section of skin through a 

 papilla. The migrating cells are observed as dark 

 bands between the epithelial cells and amongst the 

 connective tissue of the papilla. Pagenstecher. 



ward and forms the interpapillary rete Malpigliii. Wandering 

 lymphoid cells are frequently present in the rete. They are 

 especially numerous in some pathological conditions. They 

 (Fig. 118) are elongated spindle-shaped bodies lying between 

 the rete cells, and sending out minute processes. They color 



deeply in carmine, have a 

 small nucleus, and are most 

 numerous in the lower part 

 of the rete mucosum. 



The granular layer (Fig. 

 115, b) consists of one or two 

 strata of flattened, granular- 

 looking bodies, which, in 

 perpendicular section appear 

 spindle - shaped, with their 

 long diameter parallel to the 

 free surface of the epidermis. 

 In this stratum the cells are 

 no longer connected with each 

 other by bands, as in the pre- 

 ceding layer. The nuclei of 

 these corpuscles are very distinct, and flattened in the same 

 direction as the cell-body. The latter has a very coarsely gran- 

 ular appearance, which is most marked near the nucleus, and 

 gradually diminishes in degree as the periphery of the cell is 

 approached. The structure of these bodies is best shown with 

 hsematoxylon. 



The stratum lucidum, also called the stratum of Oehl, is 

 composed of at least three layers (Fig. 115, c). It presents a 

 clear, homogeneous, or striated appearance. Within the flat- 

 tened cells composing it, a staff-shaped nucleus is found. The 

 cells of this layer are formed from those of the granular stra- 

 tum. In their movement to the free surface the latter become 

 less granular and the inter-granular substance grows more trans- 

 parent and shining (Unna). This change from a granular to a 

 homogeneous translucent appearance commences around the 

 nucleus, whence it gradually extends to the periphery of the 

 cell. The nucleus, also, usually becomes invisible. 



In vertical section the corneous layer appears (Fig. 115, d) 

 to be composed of wavy fibres and horny, transparent cells 

 of various sizes and shapes. This variation in bulk and form 



