366 Dynamic Theory. 



into new tissues ( presumably governed by the peculiarity of the crys- 

 tallization and polarity of their elementary or " physiological units. ") 

 He agrees with Mr. Simon in designating several of the forms of cancer 

 as a manifestation of the existence in the blood of a peculiar matter ap- 

 propriate for the construction of such an organic structure. Mr. Simon 

 styles the cancer l ' a new excretory organ which tends essentially to 

 acts of eliminative secretion just as distinctly as the healthy liver or the 

 healthy kidney. " This is disputed, and it is said by some physiologists 

 that the matter of a cancer is composed of epithelial tissue. If this is 

 true, the cancer is to be regarded as a graft of a foreign ' ' physiological 

 unit." Papillon says that cysts (bladders) have been found in the 

 ovary ' ' containing in their inner wall a true skin furnished with papillae, 

 epidermis, hairy follicles, hairs . and perspiratory glands. Teeth even 

 have been found developing in the abdomen." 



In general, the activity of a part is the cause of an extra flow 

 of nourishment to that part. This is true of muscles and nerves. 

 After they are properly nourished they cannot be made to increase in- 

 definitely in size by the mere presentation to them of a superabundance 

 of food. The superabundance will go to the formation of a substance 

 having another constitution or mode of aggregation usually fat. But 

 there are conditions in which growth seems to be limited only by the 

 supply of food. Dr. John Hunter transplanted the spur of a cock from 

 its leg to its comb. In consequence it appears of the superior vascular- 

 ity of the comb, over the place with which the spur is naturally con- 

 nected, it receives there an increased amount of nourishment, so that it 

 continues to grow indefinitely. In one case, a spur thus transplanted 

 grew in a spiral form till it was six inches long ; and in another case it 

 curved downwards and forwards like a horn, so that its end needed to 

 be often cut to allow the bird to bring its beak to the ground in feeding. 

 The different organized entities, which together form the body of an an- 

 imal, seem to put upon each other a limit of growth, whereby a certain 

 relative proportion is preserved between the related or contiguous parts 

 which have been evolved in connection with each other. The spur on 

 the leg used in connection with the leg, and getting its nourishment 

 from the same sources, has developed in a proportional manner, deter- 

 mined by these relations. But when the spur is transplanted to an or- 

 gan with which it has heretofore not been associated and influenced, it 

 is no longer under such limitation, and may then appropriate all the 

 food in reach. 



The excessive nourishment of a part which causes its undue enlarge- 

 ment, is called hypertrophy. When there is hypertrophy of the mus- 

 cles from any cause, the associated bones are also stimulated in growth. 

 And this is shown not only in the increased size of the bones themselves 



