Having thus given answers to possible objections, let us now look into the reasons which may serve as proofs to our explanation. The first is derived from the analogy there is between expansion and reproduction; expansion cannot be explained in a satisfactory manner, without employing those penetrating powers, and those affinities or attractions we have already made use of to explain the formation of small organized beings, resembling the great ones which contain them. A second analogy is, that nutrition and reproduction are both not only produced by the same efficient, but also by the same material cause, the organic particles of the nutriment. And a proof that it is the superfluity of those particles which serves for reproduction, is the body not being in a condition to propagate before they have done growing; and we daily see in dogs, and other animals, who more exactly follow the laws of nature than we, that they nearly attain their full growth before they attempt to copulate, and by which we may know whether a dog will increase any more or not; for we may be assured he will not after being in a condition to engender. It is another proof that the superfluous nutriment forms the seminal liquor, that eunuchs, and all mutilated animals, grow larger or thicker than those who have not that deficiency. The superabundance of nutriment not being able to evacuate, for the defect of proper organs, alters the habit of the body; the thighs and haunches of eunuchs grow very large: the reason is evident; after their body has attained the common size, if the superfluous organic molecules found an issue, as in other men, this growth would no longer increase; but as there are no longer organs for the emission of the seminal fluid, which is no more than the superfluous matter which served for growth remains, it endeavours to expand the parts beyond their usual dimensions. Now it is known, that the growth of the bones is made by the extremities, which are soft and spongy, and when they have once acquired solidity, they are no longer capable of extension; and for this reason, the superfluous organic particles can only expand the spongy extremities of bones, which causes the thighs, knees, &c. of eunuchs to thicken so considerably.