228 LEISURE-TIME STUDIES. 



respect, may truly be described as a process of the readjust- 

 ment and rearrangement of the atoms and gemmules of the 

 insect's frame. The variations of living beings may in their 

 turn be explained by assuming an irregularity to exist in 

 the arrangement of the gemmules which unite to form the 

 germ of the varying form. Modified cells will give out 

 modified gemmules, and these last will produce variations in 

 the new being. Any cause producing alterations in the 

 gemmules, either in the direction of over-fertility or in that 

 of deficiency, will tell with corresponding effect on the germ 

 which they tend to form. Whilst in cases in which bodily 

 structures, mental qualities, or even diseases lie dormant in 

 one generation, and become developed in the succeeding 

 race, the gemmules may be regarded as having been 

 transmitted in a latent condition in the former race, and as 

 having been awakened and redeveloped in the latter. The 

 transmission of active disease to a particular generation 

 through an intervening and latent stage represented by the 

 preceding generation, is explicable, if we suppose that the 

 dormant condition acts on the gemmules as rest acts on 

 wearied muscles in serving to restore their pristine strength. 

 Some diseases are known to gain strength and virulence 

 after the lapse of a generation, in which they have lain 

 dormant and inactive. And the reappearance of the dis- 

 eased condition becomes connected by the explanation just 

 given, to use Mr. Darwin's words, with " the wonderful fact 

 that the child may depart from the type of both its parents, 

 and resemble its grand-parents or ancestors removed by many 

 generations." 



Not less interesting is it, however, to trace the trans- 

 mission of mental qualities, powers, and traits of disposition 

 from one generation to another. The mere fact of such 

 transmission would seem to imply the importance of the 

 physical side of mental acts, and the closer dependence of 

 mind on physical textures and nerve-tissues than is generally 

 admitted. The transmitted quality can only be regarded, 

 in fact, as having been materially and physically transmitted, 



