CONCLUSION ON BEALE'S MUSCLE THEORY. 171 



In conclusion, I have gone into this lengthened com- 

 mentary on the nerve and muscle theory from respect 

 to the high authority from which it comes, and its 

 intrinsic merits, and as it is held to be a test of the 

 theory of the sole vitality of the protoplasm. For it 

 is the most vulnerable point of Dr. Beale's views, and 

 far from being yet sufficiently proved. But if ulti- 

 mately disproved, I do not think the protoplasmic 

 theory would thereby be affected, for vitality would 

 not necessarily be attributed to anything rigid and 

 possessing structure, but only to the isotropous semi- 

 fluid contents of the muscular fibre sheath ; we would 

 simply have to accept the muscular fibre as containing 

 protoplasm, and the contraction to be a vital act just 

 as secretion is. In other respects the protoplasmic 

 theory would remain the same. The common theory 

 has at first sight nearly everything in its favour, for 

 all protoplasm is contractile, and gathers itself into a 

 ball under stimuli ; the muscular fibre also contains 

 what to the microscope appears to be protoplasm, and is 

 said even to take the carmine (see p. 132). And it is 



state whether it is a return cord essential to complete the circuit, or 

 whether it or -they, if more, are commissural or afferent to different 

 nerve centres. The whole subject of electro-dynamic actions of cur- 

 rents not closed, but with ends as in the Leyden-jar, is not yet worked 

 out by the mathematical physicists to the degree of accuracy that has 

 been attained with respect to the closed galvanic circuits, so perhaps 

 we can hardly expect any decisive theory of nerve action as yet. Bufc 

 Dr. Beale appeals to the action of the electrical eel, the force of which 

 is certainly electricity, as an example of the mode of transmission of 

 nerve force. It is not very clear how the shock of this animal is 

 transmitted, but it does not appear that a circuit is formed through 

 the animal of which the recipient forms part. Again, in the muscular 

 nerve circuits he does not state where the return cord of the nerve 

 loop is inserted ; whether all return to the spinal cord, or whether some 

 return to protoplasm masses within the muscle itself. 



