16 Dr. H. A. Cummins — A Theory of Vegetable Antitoxins. [Jan. 



this by** saying tliat a substance toxic to the fever poison is produced in 

 the tissues and that in the course of years, survival of those capable of 

 producing this antitoxin led to the existence of a fever-resisting race. 

 In a similar manner plants capable of producing a necessary antitoxic 

 substance now grow and flourish while those not so capable have become 

 extinct. I shall now endeavour to explain how I think the process may 

 take place. 



Sec. I. Experiments on absorption of plants — Bacteria, etc. — 



Symbiosis. 



We must first consider the results of certain experiments made by 

 scientists to test the powers of absorption by the roots of plants. The 

 red colouring matter of Phytolacca was absorbed by white hyacinths 

 when poured upon the soil on which they were grown : after two or 

 three days the red colour disappeared from the flowers (6ion). The 

 flowers of the tuberosa (Polyanthes tuberosa) and snapdragon were 

 affected in a similar manner (Sarrabat). Cut flowers take up colour- 

 ing matter with rapidity, as may be easily demonstrated. The injured 

 cells at the surface of the section become infected with bacteria 

 (Hohnel). The osmotic action by means of which water and substances 

 dissolved therein pass into the roots does not preclude the possibility 

 of the entrance of bacteria. Dead albuminous substances cannot pass 

 through a colloid membrane : the relation between living cells is differ- 

 ent and although the cells of the root hairs may be very capricious in 

 their action, nevertheless, living bacteria or other protophytes might 

 gain admission. Bacteria appear to be invariably unicellular and 

 amongst the minutest organisms observed by the aid of the microscope 

 varying from -^^ m.m. to gwo m.m. (Kerner and Oliver, Nat, Hist, 

 Plants, page 161). 



Besides the bacteria proper there are many protophytes which 

 consist each of a very small cell without any differentiation into cell-wall 

 and cell contents ( Sachs, Text Book of Botany, page 248). Bacteria are 

 also known to exist and float about in the air so that the possibility of 

 their entrance by the stomata of leaves must also be considered. This 

 entrance of the hyphae of Polypori is known to take place (Kerner, 

 op. cit., page 163). 



A certain relation is known to exist between Fungi and the roots of 

 plants, especially of those of the Natural Orders Ericaceae, CupuUferae 

 and Salicaceae. Here we have a symbiotic union between the fungus- 

 mycelium and the roots of a green -leaved plant, (Kerner, op. cit., 

 page 250). The hyphae insinuate themselves inside the walls of the 

 epidermal cells of the root and the latter are permeated by an extremely 

 fine meshed mycelial net (Kerner, op. cit., page 249). 



