64 Transactions Tennessee Academy of Science 



■'3 — Growth retarding bodies, which prevent the spores and thick 

 walled bacteria from germinating." 



"4 — In the plant also occurs a concomitant, perhaps also an effi- 

 cient factor, an increase in the acidity of the cell sap." He an- 

 nounces results to be embodied in a second paper showing "the 

 possibility of active and passive immunization of plants and bac- 

 tericidal bodies in them." 



In a subsequent paper representing work done during recovery 

 from a wound received on the "Northern battle front" Wagner dis- 

 cusses in detail the increase of acidity of the cell sap of plants, or 

 of hydrogen ions, as a result of infection with bacteria. Von Fiegler 

 had shown the same thing true of the blood serum of animals, as 

 expressed by a lower degree of alkalinity following infection. Wag- 

 ner regards this increase of acidity as a protective phenomenon. The 

 same result occurs after wounds in plants, and by some investigators 

 has been termed "wound fever." If Wagner makes good his claim 

 there now remains virtually a single gap in the strict identity of 

 response between animals and plants to agencies of disease. Does 

 phagocytosis exist in plants? This question seems also capable of 

 an affirmative answer. So far as I have been able to find, no one 

 has reported such a phenomenon as the engulfing of bacteria by 

 plant protoplasts. We must remember that there are no migratory 

 cells in the bodies of higher plants, and that if phagocytosis exists, 

 it must be found in the fixed body cells. We must remember, how- 

 ever, that there are fixed phagocytes even in the human body, and 

 intracellular digestion is the rule in coelenterates. 



In the first place there hardly seems any other explanation for 

 Erwin F. Smith's results with crown gall. What becomes of the 

 bacteria shown to be the cause of this disease if they are not disin- 

 tegrated by some active agent; and what other process could better 

 account for the phenomenon than phagocytosis? Phagocvtosis in 

 the root nodules of cycads has been shown by Zach, and in orchid 

 roots by Bernard. In each of these cases the parasite was a fungus. 

 This fungus is really symbiotic with the orchid, which under certain 

 conditions seems to become antagonistic or pathogenic. Bernard 

 found in many cases that the filament of the fungus clumped into 

 balls, which phenomenon he even compared to agglutination of 

 bacteria. He also found thai after one infection of an indiviihial 

 orchid seedling, a subse(]uenl infection could not be produced, in 

 other words the plant was inunune against a subsequent attack, as 



