136 SYMBIOSIS 



reactions [work, domestic and bio-economic] that have gone on and are 

 still going on within it. These reactions are nicely adjusted, and are 

 readily interfered with or encouraged by the conditions under which they 

 take place. The result is perceived in a delicate adjustment of growth 

 whereby the different parts are so correlated to each other [complete 

 domestic and biological reciprocity] that excessive development of one 

 part carries with it its own order of arrest [moderation a condition of 

 reciprocity] whilst deflection of nutrition to or from any part will, of course, 

 correspondingly effect growth in that region [the avoidance of antithetic 

 developments of growth depends upon the earning of such food as is most 

 calculated to maintain the utmost unity in the diversity of parts]. 



I should say that the instructiveness of the case of the lichen 

 consists in the proof it affords of the truth that only the right 

 kind of work can produce the right kind of reaction, both chemical 

 and biological, and, further, that the right kind of work requires 

 the right or ideal kind of food, namely, such as is non-perverting, 

 having regard to efficiency and permanence of effort and to 

 the delicate requirements of mutual accommodation by the 

 method of reciprocal differentiation. 



In telling us of the dreadful ravages of parasites amongst 

 plants, Prof. Farmer points out that we know very little, as yet, 

 about the nature of " constitutional " resistance (to disease or 

 infection), which nescience is not surprising failing the important 

 recognition that health and disease follow in the wake of two 

 antagonistic forces, represented by Symbiosis and Parasitism 

 respectively. Prof. Farmer further says that the environment 

 plays a part in increasing liability to infection, without, however, 

 attempting to specify this part, or to tell us what may be due to 

 " sociological " action and reaction as between organism and the 

 bio-social environment. We are merely told that " presence 

 of nitrogenous manure in excessive quantities " is a " predisposing 

 cause of fungal attack." " It operates in several ways, but often 

 indirectly by causing an undue accumulation of soluble nutritious 

 substances in tissues and cells, the walls of which are imperfectly 

 thickened " (a kind of "osteoporosis," in fact !). 



I would, however, point out in this connection that we have 

 here precisely an illustration of the general ill-effects of " in- 

 feeding," with its exaggerated reliance upon organic, and more 

 particularly, nitrogenous material obtained in the majority of 

 cases by the lazy method of " short cuts," i.e., without due work 

 and exercise and without due biological forbearance, such as are 

 entailed in genuine organic reciprocity. We may conclude that 



