A NATIONAL VETERINARY SCHOOL. 435 



great master of medicine, Yirchow. While we look upon the cell 

 as the unit of life, we have to pay our attention to the units of 

 which it is composed. A cell is a mass of protoplasm, with or with- 

 out an inclosing membrane, with or without a nucleus or nucleolus. 

 Changes in this protoplasm cause variations in the functions of the 

 cell. The work of the cell, the part it takes in the animal or vege- 

 table economy, is dependent upon the composition — molecular rela- 

 tions and chemical nature — of its protoplasm. This is the consti- 

 tution of the cell. If the constitution is normal, the functions of 

 the cell are normal. If the relations and nature of any of the ele- 

 ments vary to any great degree, so that the influences of the varia- 

 tions, on the part of one or a group of cells, can not be equalized by 

 the action of the others, then the functions of the cell become ab- 

 normal to a corresponding degree. Abnormality can only take 

 place in three directions — viz., a plus, a minus, and an entire cessa- 

 tion of functional activity. The sum of the cellular functions con- 

 stitutes life. The variable phenomena of lif e, in different individuals 

 of one and the same family, are invariably dependent upon varia- 

 tions in the anatomical relations, or in the protoplasm of which the 

 cells are composed, or in those organs in which such differences are ob- 

 servable. This doctrine may be traced in the early medical writings. 

 We find it intimated by the grand Greek, Hippocrates, the father 

 of medicine. His four humors — blood, black gall, white gall, and 

 mucus — gave rise to the constitution of the individual. The tem- 

 peraments were dependent upon the relations of the humors to one 

 another. The cell being considered as a unit, an indefinite number 

 of these units, collected together for one purpose, form an organ, a 

 greater unit ; and the union of a certain number of these larger 

 units, each with its special functions, each with its work to do for 

 itself, for its own existence, as well as work to do for the benefit of 

 each of the organs united with it, constitutes the functions of that 

 complex unit — if I may be allowed the term — the organism. Con- 

 sidered as a unit, the organism does not differ from the cell. Its 

 constitution is dependent upon the anatomical relations and chemical 

 composition of its elements. Its functions are dependent upon their 

 normal relation to each other for their perfect completion. Its tem- 

 perament upon the same. Man's organism has work to do to keep 

 itself in condition, as well as its part to keep the machine (unit) in 

 existence, which we call humanity. 



The diversity of intellectual " gifts " is neither special curse nor 

 special blessing. It is based upon variations in the structural rela- 

 tions, molecular proportion, or chemical conditions of the different 



