174 BOARD OF AGRICULTURE. 



development where the size remains, but the structural plan 

 is that of a lower grade of animal life, as in malformed beasts, 

 where development makes no progress, but the growth goes 

 on to beyond the ordinary bounds. 



Let me enunciate a few general laws which may be deduced 

 from what is thus far written. 



Each cell contains its proper formative force which deter- 

 mines its future. 



The force contained within each cell may be increased or 

 diminished through its environment. 



Each cell receives its development to such an extent as is 

 determined by the forces which it has or may receive, — no 

 more, no less. 



Complexity of environment requires in the cell a greater 

 force of resistance and more changes, in order that an equilib- 

 rium may be established, than simplicity of environment. 



The order or sequence of development is the same as that 

 in which the force which determines the development was 

 received. In other words, persistence of force requires an 

 evolution, a progress onward so long as increased complexity 

 of function is required, and the forces appropriated are suffi- 

 cient to establish the equilibrium ; and the law of inheritance 

 requires that the force shall act in the order in which they 

 were received, for the sum of the past forces is essential to 

 the formation of the new concrete force. 



The general law of matter, that like causes produce like 

 effects when acting on the same material, also finds expression 

 in this connection. This is illustrated by symmetrical diseases. 

 As Pasret remarks, the morbid substance in the blood, " fastens, 

 for instance, on certain islands on the surfaces of two bones, 

 or of two parts of the skin, and leaves the rest unscathed, and 

 these islands are the exactly corresponding pieces upon oppo- 

 site sides of the body. The conclusion is unavoidable, that 

 these are the only two pieces that are exactly alike ; that there 

 was less affinity between the morbid material and the osseous 

 tissue, or the skin, or the cartilage, close by, else it also would 

 have been similarly diseased." If we understand by affinity 

 the expression in a partial form of this law of forces, the 

 matter is rendered more intelligible. The like portions of 

 the body, the symmetrical ones, are developed through like 



