VI ANIMALS AND PLANTS 195 



the probability that the Peronospora is nourished 

 directly by the protoplasm of the potato-plant; 

 and the wonderful facts which have recently been 

 brought to light respecting insectivorous plants, all 

 favour this view ; and tend to the conclusion that 

 the difference between animal and plant is one of 

 degree rather than of kind, and that the problem 

 whether, in a given case, an organism is an 

 tuiimal or a plant, may be essentially insoluble. 



