IOO PLANT RESPONSE 



In all the above respects, we find that the responses of 

 plants in general exhibit the closest parallel to the responses 

 of skeletal muscle in animals. 



But in the animal a different type of response is exhibited 

 by certain rhythmic tissues like cardiac muscle. The re- 

 sponse here is on the ' all or none ' principle, and such a tissue 

 cannot be tetanised. In the parallel instances of rhythmic 

 vegetable tissues, the same characteristics are present ; that 

 is to say, the responses are on the ' all or none ' principle, and 

 there is no tetanus. 



