EPITHELIAL CARCINOMATA. 201 



character on every variety of primary epitheliomatous growth.* 

 It is not therefore as glands, but as appendages of the epidermis, 

 that the sebaceous and sudoriparous follicles take part in the 

 proliferation. They lose their glandular character and are con- 

 verted into what they originally were, solid aggregates of cells, 

 forming peg-shaped appendages of the under surface of the 

 epidermis. 



§ 167. Opinions differ concerning the way in which the epi- 

 thelial sprouts grow and penetrate mto the sub-epidermic layer of 

 connective tissue. According to Thiersch^ Billroth and others, 

 the sprouts grow exclusively by proliferation of their epithelial 

 elements ; Kostev holds that their increase is additive, and due to 

 a corresponding metamorphosis of the endothelial cells of the 

 lymphatics, in whose interior the sprouts exclusively extend. 

 For my own part, I cannot overlook the very striking fact, that 

 active fission of cells and nuclei may be seen to take place in the 

 sprouts themselves ; neither can I ignore the eloquent appearances 

 exhibited by sections taken from the raised border of certain flat 

 epitheliomata in a direction parallel to their surface, as Koster 

 recommends. 



Fig. 64 exhibits the superficial lymphatic network of the 

 cutis in its highly characteristic configuration, but with its 

 interior occupied by cylindrical masses of epithelial cells. The 

 lymphatics in this specimen are undoubtedly the channels along 

 which the epithelial sprouts advance. It must not be inferred 

 from this, that they perfoi'm a like office in the case of all 

 cancers ; indeed we may find it necessary to admit that the 

 interesting appearances discovered by Koster are only the micro- 

 scopical expression of a fact already known, sc. that cancers and 

 sarcomata of glandular organs (^e.g. of the kidney, the testicle, 

 the lymphatic glands) are especially prone to penetrate into the 

 interior of the blood-vessels and lymphatics, in which they sub- 

 sequently extend. Whatever be our conclusion, the observatipn 



* From an examination of epitheliomata of the digestive tract, I have 

 come to the conclusion, that the tubular glands of the mucous mem* 

 brane, lined with columnar epithelium, play the same part as the seba- 

 ceous glands of the skin. They extend inwards, and change their 

 character, losing their central cavity, and forming solid aggregates of 

 cells ; these aggregates consisting first of indifferent elements, subae- 

 cpiently of true squamous epithelia. 



