40 SYMBIOSIS 



else," are almost the only animal types without wandering 

 phagocytes the microscopic symbiotic defenders, discovered 

 by the late Prof. Metchnikoff, which play so great a part in 

 safeguarding the blood of animals against the attacks of injurious 

 microbes. 



When Dr. Russell in a subsequent paper* develops the idea 

 of an apparent paradox " that any process fatal to life (but not 

 too fatal) proves ultimately beneficial to fertility, while any 

 process beneficial to life proves ultimately harmful," I would 

 demur. I see no paradox whatsoever in the fact that only 

 conditions favourable to Symbiosis are favourable to life in a 

 real sense, and that on the other hand surfeiting conditions 

 however acceptable the materials provided would normally be 

 in so tar as they interfere with efficiency of work and of 

 Symbiosis, thus preparing the soil for pathogenic and parasitic 

 rather than strenuous and progressive developments, are really 

 unfavourable to life. 



Long frost, drought, heat (says Dr. Russell), benefit the useful makers 

 of plant food, while prolonged warmth, moisture and treatment with organic 

 manures lead to deterioration or to " sickness " as the practical man 

 puts it. 



But this is really only saying that in cultivation anything 

 which favours honest labour and Symbiosis at the expense of 

 Parasitism, proves in the long run more favourable to life than 

 anything which favours Parasitism at the expense of honest toil 

 and Symbiosis a truth which is borne out universally and which 

 can lend itself to paradoxes only so long as we fail to draw a clear 

 distinction between the reciprocal and the non-reciprocal, the 

 normal and the abnormal, modes of life. 



In my book on Symbio genesis I have stressed the fact, 

 brought to light by recent horticultural investigation at the 

 Woburn Experimental Fruit Farm, that ramming the soil round 

 the tree at the planting has beneficial effects upon growth. It 

 means bringing the roots into intimate contact with the soil, 

 which ensures an ample supply of mineral substances. The 

 salubrious effects of intimate earth-contact in this case, I hold, 

 are due to the fact that it affords to the tree a direct draft upon 

 ideal plant-food, that it entails the most complete " cross- 

 feeding." 



The flower must drink the nature of the soil before it can put forth 

 its blossoming. 



* Nature, Vol. 97, No. 2,433, p. 332. 



