APPLICATIONS OF THE GRAPHIC METHOD. 20% 
It is a remarkable fact that the endurance of man, especially 
civilized man, seems to be greater than that of any other mam- 
mal. It may be hazardous to express a dogmatic opinion as to 
the reason of this, but the influence of the mind over the body 
is unquestionably greater in man than in any other animal; 
and, if we are correct in assigning so much importance to the 
influence of the nervous system in maintaining the proper 
molecular balance which is at the foundation of the highest 
good of an organism, we certainly think that it is in this direc- 
tion we must look for the explanation of the above-mentioned 
fact, and much more that would otherwise be obscure in man’s 
functional life. 
Functional Variations. We have endeavored, in treating this 
subject of muscle, to point out how the phenomena vary with 
the animal, the kind of muscle, and the circumstances under 
which they are manifested. It may be shown that every one 
of the qualities which a muscle possesses, varies with the tem- 
perature, the blood-supply, the duration of its action, the char- 
acter of the stimulus, and other modifying agents. Not only 
are there great variations for different groups of animals, but 
lesser ones for individuals; though the latter are made more 
evident indirectly than when tested by the usual laboratory 
methods; but they must be taken account of if we would un- 
derstand animals as they are. Some of these will be referred 
to later. 
If a muscle-cell be regarded in the aspect that we are now 
emphasizing, its study will tend to impress those fundamental 
biological laws, the comprehension of which is of more impor- 
tance than the acquisition of any number of facts, which, how- 
ever interesting, can, when isolated, profit little. 
Experiment has not done much directly, and it seems can 
not at present, for the physiology of man, though more may be 
accomplished as regards muscle and nerve than some other 
tissues. It is, of course, possible to measure the rapidity of 
the passage of a nervous impulse and to study electrical phe- 
nomena generally to some extent. Putting all that is known 
together, it would appear that,.without referring to minor dif- 
ferences which unquestionably exist, the muscle and nerve 
physiology of man corresponds pretty closely with that of one 
of the highest mammals, and, as compared with the lower ver- 
tebrates, his muscles and nerves possess an irritability of a 
very exalted type, with, however, a corresponding loss or dif- 
ference in other directions. 
