As once more we search backwards, tracing the differences of sex function to their earliest appearance in the humblest types of life, we find the exact opposite of this theory of the inferiority of the female to be true. The female is of more importance than the male from Nature's point of view. We have seen that life must be regarded as essentially female, since there is no choice but to look upon asexual reproduction as a female process; the single-cell being the mother-cell with the fertilising element of the father or male-cell wanting. We know further that a similar process, but much more highly developed, is possible in what is called parthenogenesis, or virgin-birth, which can only be explained as a survival of the early form. For long life continued without the assistance of the male-cell, which, when it did arise, was dependent on the ova, or female-cell, and was driven by hunger to unite with it in fatigue to continue life. We are thus forced to regard the male-cell as an auxiliary development of the female, or as Lester Ward ingenuously puts it, "an after-thought of Nature devised for the advantage of having a second sex." Now, if we examine the simplest types of the sexes in the lower reaches of the animal kingdom,[18] below the vertebrates we find the same conditions prevailing. The male is frequently inconspicuous in size, of use only to fertilise the female, and in some cases incapable of any other function; the female, on the other hand, remains unchanged and carries on the life of the species. So marked is this difference among some species that the male must be regarded as a fallen representative of the female, having not only greatly diminished in size, but undergone thorough degeneration in structure.[19] In certain extreme cases what have been well called "pigmy males" illustrate this contrast in an almost ridiculous degree. This is well seen among the common rotifers, where the males are much smaller than the females and very degenerate. Sometimes they seem to have dwindled out of existence altogether, as only females are to be seen; in other cases, though present they fail even to accomplish their proper function of fertilisation, and as reproduction is carried on by the females, they are not only minute but useless. Nor are such cases of male degeneration confined to this group. The whole family of the _Abdominalia_ (cirripedes) have the sexes separate; and the males, comparatively very small, are attached to the body of each female, and are entirely passive and dependent upon her.[20] Some of these male parasites are so far degenerated as to have lost their digestive organs and are incapable of any function except fertilisation: the male _Sygami_ (menatodes), for instance, being so far effaced that it is nothing but a testicle living on the female.[21] A yet more striking instance is furnished by the curious green worm _Bonellia_, where the male appears like a remote ancestor of the female, on whom