482 LAWS OF MULTIPLICATION. 



dence. Obesity not uncommonly sets in after the system has 

 been subject to debilitating influences. Often a serious illness 

 is followed by a corpulence to which there was previously 

 no tendency. And the prolonged administration of mercury, 

 constitutionally injurious as it is, sometimes produces a like 

 effect. 



Closer inquiry verifies the conclusion to which these facts 

 point. The microscope shows that along with the increase of 

 bulk common in advanced life, there goes on what is called 

 " fatty degeneration : " oil-globules are deposited where there 

 should be particles of flesh — or rather, we may say, the 

 hydrocarbonaceous molecules locally produced by decom- 

 position of the nitrogenous molecules, have not been replaced 

 by other nitrogenous molecules, as they should have been. 

 This fatty degeneration is, indeed, a kind of local death. 

 For so regarding it we have not simply the reason that an 

 active substance has its place occupied by an inert substance ; 

 but we have the further reason that the flesh of dead bodies, 

 under certain conditions, is transformed into a fatty matter 

 called adipocere. 



The infertility that accompanies fatness in domestic 

 animals has, however, other causes than that declining con- 

 stitutional vigour which the fatness commonly indicates. 

 Being artificially fed, these animals cannot always obtain 

 what their systems need. That which is given to them is 

 given expressly because of its fattening quality. And since 

 the capacity of the digestive apparatus remains the same, 

 the absorption of fat-producing materials in excess, implies 

 defect in the absorption of materials from which the 

 tissues are formed, and out of which young ones are built 

 up. Moreover, this special feeding with a view 



to rapid and early fattening, continued as it is through 

 generations, and accompanied as it is by a selection of indi- 

 viduals and varieties which fatten most readily, tends to 

 establish a modified constitution, more fitted for producing 

 fat and correspondingly-less fitted for producing flesh — a 



