THE KINSHIP OF LIFE. 27 
of the structure. For “natural selection” must, in a 
way, be operative among the organs of the body. “Die 
Kampf der Theile,” as it has been called by a German 
writer (“the battle of the parts”), is a real struggle in 
which fitness determines survival. 
It is not merely the simple structures and the com- 
mon instincts which may be developed and fixed by 
natural selection. 
The differentiation of the sexes is a result of the 
demand for greater variation. It is the fact of bisexual 
parentage that makes of each individual 
not simply an “elongation or continu- 
ance of the parent,” but a new life 
which shall be the resultant of the lives 
and experiences of its ancestors, a mosaic of the char- 
acters of its parents and its parents’ parentage. By the 
fact of sex no individual can be the mere slavish copy 
of any other. Through the operation of sex the law 
of heredity which is to promote sameness is made sub- 
servient to the equal need of the promotion of variety. 
This idea of the formation of the mosaic of per- 
sonal character is the motive of Goethe’s 
“Vom Vaterhab’ famous poem, Vom Vater hab’ ich die 
ich die Statur.” 
How bisexual 
parentage brings 
variety. 
Statur.* 
* “Vom Vater hab’ ich die Statur, 
Des Lebens ernstes Fuhren ; 
Vom Mutterchen die Frohnatur 
Und Lust zu fabuliren. 
Urahnherr war der schonsten Hold, 
Das spukt so hin und wieder. 
Urahnfrau liebte Schmuck und Gold, 
Das zuckt wohl durch die Glieder. 
Sind nun die Elemente nicht 
An dem Complex zu trennen ; 
Was ist denn an dem ganzen Wicht 
Original zu nennen?”—GoETHE, Zahme Xenien, vi, 
