580 THE SKIN. 



columnar epithelia, partly filled with minute fat-granules j acini 

 are wanting. 



In male adults the mammary gland exhibits a structure simi- 

 lar to that of the new-born infant ; real acini do not exist, even 

 though the gland may attain a considerable size. 



The lowest layers of the rete mucosum of the nipple and its 

 areole contain pigment granules ; the papillae are very large and 

 branching, and have either capillary loops or tactile corpuscles. 

 The derma is freely supplied with bundles of smooth muscle- 

 fibers in a reticular arrangement; they are twined around the 

 lacteal ducts in a vertical direction. 



Within the areole the connective tissue of the derma and the 

 subcutaneous layer is free from fat. During the latter months 

 of pregnancy small granular elevations are found in the areole, 

 which are sebaceous glands, emptying at the height of the 

 granule. They have been erroneously described as accessory 

 cutaneous lacteal glands. Occasionally they give rise to an 

 active glandular new formation, with the production of a 

 sebaceous adenoma. 



Inflammation of the Skin.* I have studied the process of inflammation of 

 the skin in specimens from a syphilitic papule ; from small-pox ; from an 

 ' ulcerating sac of umbilical rupture in a cat. I have investigated the termina- 

 tions of inflammation in specimens of elephantiasis of the scrotum and of the 

 labia majora. Inflammation as an accompanying process I have studied in 

 the skin of the female breast in mastitis and cancer, and also in the skin 

 covering different benign and malignant tumors, or directly involved in 

 the formation of such tumors. The results in all these cases being almost 

 identical in regard to the essential changes in the tissues of the skin, I can 

 confine myself to the description of the inflammatory process in small-pox, 

 of which I obtained six different specimens from the BlackwelPs Island Hos- 

 pital ; among these were two of heemorrhagic small-pox. 



The coarser microscopical features in the formation of small-pox have been 

 accurately studied by Auspitz and Basch. The essential structural changes 

 observable with high magnifying powers of the microscope, 800-1200 

 diameters, and which can be understood only upon the knowledge of the 

 normal anatomy of the affected tissues, are as follows : 



First, the epithelial layer, termed rete mucosum, appears slightly thick- 

 ened in circumscribed spots ; the swelling is due to a coarse granulation of 

 the epithelia themselves. This granulation is produced by an increase of 

 living matter within the epithelia, evidently through an augmented afflux of 

 nourishing material during the stage of hypereemia. The points of intersection 

 of the net-work of living matter, the so-called granules, become enlarged, 

 many of the nuclei are solid and shining, and at the same time the threads 



! " Microscopical Studies on Inflammation of the Skin." A paper read before the Ameri- 

 can Dermatological Association at their meeting in New- York, August 27, 1879. Published 

 in abstract in The Chicago Medical Journal and Examiner, October, 1879. 



