26 PROCEEDINGS OF THE ACADEMY OF [1887. 



able, and considerably different from that of the normal tissue 

 of the body-mass of the animal. The sections also showed that 

 the tumor was traversed by vessels, the tissues immediately 

 around which were more nearly of the kind normally found to 

 constitute the greater j^art of the substance of the body-mass. 

 The normal connective tissue is composed of large cells or spaces 

 with thin walls, and about the centre of each one of these a 

 small, complex mass of protojilasm is found Avhich is suspended 

 to the sides of its vesicular wall by means of fine radiating pro- 

 toplasmic threads or filaments. Very minute nucleated and 

 rounded blood and lymph cells are also found in the general con- 

 nective tissue of the body-mass in small numbers. 



The histological structure of the tumor contrasts with the 

 normal tissue in the following particulars. We find no evidence 

 of the presence of the central protoplasmic bodies, with radiating 

 processes, in the meshes of the tissue. The mesh of the tissue 

 of the tumor is areolar, or alveolar, the alveoli being much larger 

 than the vesicular cells of the normal connective tissue. While 

 there is a complete absence of the ^protoplasmic bodies with fila- 

 ments, the alveoli contain great numbers of very small globular, 

 nucleated cells, somewhat variable in size. These cells closely 

 resemble the colorless blood and lymph cells of the oyster, and 

 some show processes or pseudopods. They are generally adherent 

 to the walls of the alveoli, or project in small adherent clumps 

 from the parietes of the alveoli and never completely fill the 

 meshes of the alveolar tissue, in which they are included, as do 

 the analogovis cells in the alveoli of tumors in the higher animals. 



Near the centre of each nodule there is a zone of alveoli which 

 are larger, and in which the small rounded cells are most abund- 

 ant. At the surface of the tumor there is no investment of a 

 truly integumentary character, so that the proliferating mass 

 seems to have ruptured the integument or membrane lining the 

 pericardium. At the surface we therefore find that there is no 

 true integument, but instead, the alveoli become smaller and 

 more compact, with the contained small rounded cells more 

 closely packed. The tissues of the tumor are entirely of meso- 

 dermal origin, and are therefore of considerable interest from the 

 standpoint of comparative pathology. 



The speaker also referred to the presence of tumors, which 

 developed as outgrowths of the intestinal wall, near the pylorus, 

 in the common shad, and also instanced the occurrence of pro- 

 found lesions of the Wolffian body or kidney of the common 

 gold-fish, as a result of which that organ underwent complete 

 degeneration, with other changes which caused a bloated, drop- 

 sical appearence in the cavity of the abdomen. Large meshes of 

 fibrous tissue were, in fact, found occupying the place of the 

 kidney filled with a Avatery or colloid substance, the whole taking 

 up a much greater space than that originally filled by the normal, 

 organ. These data, the speaker thought, were very significant, 



