42 STATE BOARD OF AGRICULTURE. 



can one secure such a wholesome knowledge of enzymic action? With 

 these lower forms, every enzyme knoAvn to life may be found, and it 

 may be studied with such exactness in its relations to life that to take 

 it apart from this simple life, usually leads to false conclusions. The 

 manufacture and secretion of enzymes by the cell, the agents which 

 influence these processes, — all factors wliich in one Avay or another 

 control them may be studied with a degree of minuteness which can- 

 not be attained by studies in tlie human body. Osmotic ])rocesses in 

 cells can nowhere be followed out with so much satisfaction as with 

 bacterial cells which ma,y be cultivated at will, handled at will, and 

 made to respond to the various agents to which we nmy see iit to sub- 

 ject them. The adjustment of protoplasm to different conditions, differ- 

 ent stimuli, and different nutrients and its possible alterations may be 

 a matter of precise calculation. Proto])lasmic activity as manifested 

 in cell metabolism may be investigated and reached Avith comparative 

 ease whereas in the more complex structures we have to content our- 

 selves with only remote products. 



It has been found that the logic of man, wliich is too frequently em- 

 ployed, cannot in any way account for the nutritive processes of uni- 

 cellular life. Logic is faulty and very dangerous. For instance, some 

 cells are found dependent upon a living host; others may live upon dead 

 organic matter; and then there are others which are contined for theii- 

 sustenance entir-ely to inorganic comi)ounds. We find, too, that the 

 food of these unicellular plants may be altered in many ways, and by 

 so doing, the character of the nutritive processes of these jiving forms 

 is altered. It is fair to suppose, therefore, that with a knowledge of 

 these micro-organisms, far-reaching conclusions would not be drawn 

 in regard to more complex forms Avithout more positive knowledge than 

 we noAV have at hand. To suppose that different tissues require differ- 

 ent elements for their sustenance seems very reasonable to the human 

 mind, but it is not safe to say that these elements are procurable in only 

 one form, or from only one source. Substances may be found to fur- 

 nish building material and energy in the body, but to just what degree 

 they are capable of doing this is quite another matter. We are led to 

 these conclusions simply from study of single cell life. So it is that 

 many astute Avorkers are not so ready to utter conclusions as is usually 

 the case Avith those Avho are less ac(]uainted with sucli simple life mani- 

 festations (and already some Avorkers are basing Iheir work on nutri- 

 tion u])on bacteriological facts). In striving, therefore, for a knowl- 

 edge of life -problems as represented in higher animals or plants, many 

 obstacles are met Avhich cannot be surmounted. Such a ])oiiit has been 

 reached that Avhen a clue is given workers tiock to it, and keep reiter- 

 ating results until they become so heavy and so massive that to see 

 their simplicity or their pertinency, or to ])roperly value their signifi- 

 cance becomes very ii-ksome. In bacteriological work, iiowever, mat- 

 ters are so simplified that the main line of research or thought, or the 

 main line of study may be kept constantly before the mind, and experi- 

 mental evidence produced, and every bit of energy devoted to it, without 

 any diA'erting accessories in burdensome quantities. 



It may be desirable to recall the general i)hysi()h)gical knowledge 

 which has been derived from the study of preciijitins, agglutinins, 

 lysins, and anti-toxins. All of these have emanated from bacteriological 



