28 H. L. 



plant fluids were endowed with a gerraicidal property for the pro- 

 tection of the plant. If the plant possessed such a peculiarity, an 

 examination of the cell sap, with this point in view, ought to indicate 

 its presence. The first difficulty to be met with, however, is to 

 secure the cell sap free from solid elements and in an aseptic con- 

 dition. This can be accomplished without serious difficulty in the 

 case of the blood, but as there is no special channel for the move- 

 ment of the plant fluids, the problem here is not so easily solved. 



In a foregoing set of experiments, in which different species of 

 bacteria were artificially introduced into the plant-tissues, it was found 

 in a number of cases, particularly with saprophy tic forms, that they 

 had multiplied to a limited extent. This at first might indicate that 

 the plant-juices had no germ-destroying power. Such a conclusion 

 need not necessarily follow. It has already been found that the 

 germicidal action of the body fluids towards certain organisms has 

 a definite limit, and that when too many germs are brought in con- 

 tact with it its capacity for destroying the bacteria is overcome, 

 and the germs are able to increase and call forth a pathological con- 

 dition in the body. That such might have been the case in the 

 above experiments was possible, as large numbers of bacteria were 

 introduced into the plant. 



To determine this, experiments were carried out on plant-tissues 

 to determine if the plant-juices possessed any germicidal properties. 

 Heating could not be resorted to as a means of sterilization, as this 

 would affect any property analogous to the germ-killing peculiarity 

 of the blood, so the only recourse was to obtain the juices aseptically. 

 Trituration in a small sterilized mortar was first attempted, but this 

 method was regarded as unsatisfactory on account of the cellular 

 detritus present. Expression of the juice was then tried by com- 

 pression. A small screw press, capable of being sterilized, was used 

 for this purpose, and as the fluid escaped through the minute open- 

 ings in the bottom it was caught in a sterilized receiver and pipetted 

 into small culture bulbs as before. By this process the plant-juice 

 was secured perfectly free from solid particles. Into this culture 

 fluid a number of germs were inoculated, as determined by NuttallV 

 device for accurate quantitative work, and at varying intervals of 

 time the germ-contents of the bulbs were determined. In each case 



'Nuttall: Bull. J. H. H. No. 13, May-June, 1891. 



