1 877.] Our Six-footed Rivals. 439 
ant-hill ; but within each caste all are on an exactly equal 
footing. 
If we compare the zoological rank of our “ six-footed 
rivals ” with our own, we must, from one point of view, 
concede them a higher position. The more perfectly deve- 
loped is any animal the more do we find it possessed of an 
especial organ for the discharge of every function. In like 
manner it may be contended that, as a species rises in the 
scale of being, duties once indiscriminately performed by 
all the species are assigned to distinCt individuals. Among 
the humbler groups of the animal kingdom the whole repro- 
ductive task is performed by all members of the species. 
In other words, hermaphroditism prevails. As we ascend 
to higher groups the sexes are separated, and the species 
becomes dimorphous. This arrangement prevails among all 
vertebrate animals, and among a large majority of annulose 
species. We find here already, however, one of those con- 
trasts which so often prevail between these two great series 
of beings. Among vertebrates, and especially in mankind, 
the function of the female sex seems limited to the nurture 
— intra- and extra-uterine — of the young. Were man im- 
mortal and non-reproduCtive, woman’s raison d'etre would 
disappear. Among Annulosa the very reverse holds good ; 
the females are as a rule larger, stronger, and more long- 
lived, whilst the task of the male seems limited to the 
fecundation of the ova. This being once performed, his 
part is played. Among butterflies, moths, and ants his 
death speedily follows, whilst among spiders he is generally 
killed and devoured by his better-half. This predominance 
of the female sex seems to prepare the way for the pheno- 
menon which we recognise among the social Hymenoptera. 
Here the species become no longer dimorphous, but poly- 
morphous. In other words, in addition to the males and 
females, whose task is now exclusively confined to the mere 
function of reproduction, there are, as we have seen, one or 
more forms of females, sexually abortive, but so developed 
in other respeCts as to form the castes of workers and 
fighters, upon whom the real government of the ant-hill 
belongs, who provide for its enlargement, well-being, and 
defence. 
It may, we think, be legitimately contended that the deve- 
lopment of a distind working order is a step in advance 
similar to that taken by the distribution of the sexual func- 
tions among two different individuals— that the polymorphic 
species is higher than the dimorphic, just as the dimorphic 
is higher than the monomorphic. 
