102 HABIT AND INTELLIGENCE. [cHAP. 



force of tlieir muscles, as measured by the weight they 

 were able to raise, was twice as great as when they were 

 uninjured.^ This, I think, when taken together with Sir 

 Benjamin Brodie's experiment, affords direct and conclusive 

 proof that in an animal with divided spinal cord the 

 vital energy accumulates in the muscles, where it manifests 

 itself by the greatly increased force with which they con- 

 tract ; while in an animal with uninjured nervous system, 

 nervous agency determines the transformation of the vital 

 energy into either heat or motor energy, and does not 

 permit it to accumulate in so great a degree.^ 



It needs no proof that all animals produce motor energy. 

 Most of them move about, and even those which are 

 rooted, like corals and sponges, have tentacles or cilia, 

 which they move. And, as we have seen, there is good 

 reason for believing that animals have the power of storing 

 vital energy, which they can afterwards convert into motor 

 energy or into heat. 

 Motive It is not so easy to prove that aU this is true of vege- 



v°^r"1°p,s. tables : nevertheless I believe it is also true of them. The 

 motion of the germs of sea-weeds is the most remarkable 

 instance of motion in the vegetable kingdom : they move 

 so actively through the water that they have often been 

 mistaken for microscopic animals. But some degree of 

 motive power appears to be universal in the "germinal 

 matter" of vegetables as well as of animals. 



" The substance called protoplasm ^ exhibits changes of 

 form, and other movements, which cannot be explained by 



1 Dr. Norris's Eeport on Muscular Irritability, referred to in a pre- 

 vious note. Dr. Norris thinks, as I do, that this experiment proves that 

 the muscles have the power of storing energy (or force, as he calls it). 



2 It is perfectly safe thus to reason from one organic species to another, 

 for the fundamental laws of life are the same in all. Of course, this prin- 

 ciple must be applied with caution ; but as the frog and the rabbit agree 

 in the general plan of the nervous system, and in having red blood- 

 corpuscles, we are quite safe in assuming ouch an analogy between them 

 as makes the two experiments comparable and parallel. 



^ Protoplasm is what Dr. Beale calls "germinal matter," and what 

 I have called " unformed but formative material. " The latter expression, 

 however, is not suited to be a technical one, and I intend to call it 

 " germinal matter." It is found in all living organisms whatever. 



vegetables. 



