364 yournal of Comparative Neurology and Psychology. 



4. Where interaction takes place and units tend to combine, 

 the form of combination and even the possibihty of combination 

 may depend on the compatibihty ol the respective modes of motion 

 (types of activity or locus formulae). The stability of the resulting 

 complex will be determined by the nature of the resultant. This 

 question of stability may be examined mathematically, but may 

 be illustrated to the eye by the figures produced by compound 

 harmonic motion as seen in Lissajous' figures described beyond. 



5. The stability of such a complex may be very great and still 

 permit a wide range of variability within certain critical limits 

 beyond which dissolution will be rapid. Mathematical illustra- 

 tions of conditions of stability may be derived from the study of 

 the gyroscope and the behavior of vortex rings. 



6. In the case of the organic body each individual is the result 

 of the elimination of incompatible types of motion and the estab- 

 lishment of elastic but real limits of variation (heredity and 

 habit) and all this is imperfectly and to a small extent mirrored in 

 structural constants accessible to our examination. One system 

 of coordination involves within it numerous others of a second 

 order and so on indefinitely to an inconceivable degree of compli- 

 cation. From the above it is seen that a study of structure must 

 be supplemented by a still more minute study of behavior (function), 

 and the latter may be used greatly to supplement the information 

 derived from structure rather than simply to be regarded as a result 

 of the latter. Mendel's laws aptly illustrate the fact that behavior 

 points to mathematical coordinations of activities not indicated 

 in the vaguest manner in the structure of the germ. 



7- Of the continuous stream of energy which passes through 

 the organism only such parts are assimilated as can be made to 

 agree with or fit into the locus formulae already established with- 

 out too greatly altering them. An entirely antagonistic type of 

 activity may, if sufficiently violent, topple over the equilibrium 

 already established, or to use a different illustration, break up the 

 compound harmonic motion, and such degeneration may be cumu- 

 lative (poisons). 



8. It follows from what has been said that the organism must 

 have all its parts impressed with the effects of the whole in such a 

 way that any part will bear the hall mark of the individual as 

 specific characters. Thus if the integrity of the whole were dis- 

 turbed, as by mutilation, the tendency would exist to restore the 



