28 SYMBIOGENES1S 



In my little work on Evolution by Co-operation, I 

 have already pointed out that reproduction itself enters the 

 service of general production as instanced in particular 

 by " love-foods," i.e., the bye-products of plant-reproduction, 

 which as exchangeable surplusage and in virtue of 

 their high adequacy as food for the animals, are of such 

 enormous currency value in organic civilisation. Here, where 

 the value of symbiotic production is becoming more especially 

 apparent, it is incumbent on me to expand on this subject of 

 " love-foods " which has already been mentioned in connection 

 with the analogy between secretions by Convoluted coloured 

 cells and those of the mammary gland. I have there already 

 hinted that sexual symbiosis in the plant is productive of 

 " love-foods " which are in turn of high significance in 

 biological symbiosis. 



"Love-foods" milk, the date, the raisin, the banana, 

 and the bread-fruit, the locust and the honey, the eggs, the 

 grains, the cereals and the legumes constitute the great bulk 

 of the foods of the world. If Prof. Keeble states that the food- 

 material manufactured by the plant in excess of immediate 

 needs is the lever which makes the whole world of animal life 

 to move, this is pre-eminently true of " love- foods." "Love- 

 foods " are not only responsible for mechanical energies, but 

 also largely through many subtle qualitative influences for the 

 physiological and psychological elevation, i.e., for the evolu- 

 tion of the animal. In the joint evolution (rise of type) of 

 plant and animal, a place of first importance must be accorded 

 to " love-foods." It is greatly due to their increasing effective- 

 ness and adequacy, I assert, that eventually the pace of 

 evolution became much quickened a phenomenon otherwise 

 appearing as extremely puzzling. 



Herbert Spencer already emphasised as significant the 

 fact that whereas in other parts of the plant the genesis of heat 

 is extremely small, those portions only, as flowers and ger- 

 minating seeds, in which considerable oxidation is going on, 

 have a decidedly raised temperature an indication that 



