274 
THE PRINCIPLES OF 
Part II. 
or by the spontaneous movements of the stamens ; and 
with the Algse, &c., by the locomotive power of the 
antherozooids. With lowly-organised animals perma- 
nently affixed to the same spot and having their sexes 
separate, the male element is invariably brought to 
the female ; and we can see the reason ; for the ova, 
even if detached before being fertilised and not re- 
quiring subsequent nourishment or protection, would 
be, from their larger relative size, less easily transported 
than the male element. Hence plants 14 and many of 
the lower animals are, in this respect, analogous. In 
the case of animals not affixed to the same spot, but 
enclosed within a shell with no power of protruding any 
part of their bodies, and in the case of animals having 
little power of locomotion, the males must trust the 
fertilising element to the risk of at least a short transit 
through the waters of the sea. It would, therefore, be 
a great advantage to such animals, as their organisation 
became perfected, if the males when ready to emit the 
fertilising element, were to acquire the habit of ap- 
proaching the female as closely as possible. The males 
of various lowly-organised animals having thus abori- 
ginally acquired the habit of approaching and seeking 
the females, the same habit would naturally be trans- 
mitted to their more highly developed male descen- 
dants ; and in order that they should become efficient 
seekers, they would have to be endowed with strong 
passions. The acquirement of such passions would 
naturally follow from the more eager males leaving a 
larger number of offspring than the less eager. 
The great eagerness of the male has thus indirectly 
14 Prof. Sachs (‘ Lehrbuch der Botanik/ 1870, s. 633) in speaking of 
the male and female reproductive cells, remarks, u verhalt sich die eine 
“ bei der Vereinigung activ, . . . die andere erscheint bei der Yerein- 
igung passiv.” 
