The _testiculi_, stones or testicles (so called because they testify one to be a man), turn the blood, which is brought to them by the spermatic arteries into seed. They have two sorts of covering, common and proper; there are two of the common, which enfold both the testes. The outer common coat, consists of the _cuticula_, or true skin, and is called the scrotum, and hangs from the abdomen like a purse; the inner is the _membrana carnosa_. There are also two proper coats--the outer called _cliotrodes_, or virginales; the inner _albugidia_; in the outer the cremaster is inserted. The _epididemes_, or _prostatae_ are fixed to the upper part of the testes, and from them spring the _vasa deferentia_, or _ejaculatoria_, which deposit the seed into the _vesicule seminales_ when they come near the neck of the bladder. There are two of these _vesiculae_, each like a bunch of grapes, which emit the seed into the urethra in the act of copulation. Near them are the _prostatae_, about the size of a walnut, and joined to the neck of the bladder. Medical writers do not agree about the use of them, but most are of the opinion that they produce an oily and sloppy discharge to besmear the urethra so as to defend it against the pungency of the seed and urine. But the vessels which convey the blood to the testes, from which the seed is made, are the _arteriae spermaticae_ and there are two of them also. There are likewise two veins, which carry off the remaining blood, and which are called _venae spermaticae_. FOOTNOTES: [4] Seminal vesicle. [5] Urinary vesicle. * * * * * CHAPTER XVII _A word of Advice to both Sexes, consisting of several Directions with regard to Copulation._ As Nature has a mutual desire for copulation in every creature, for the increase and propagation of its kind, and more especially in man, the lord of creation and the masterpiece of Nature, in order that such a noble piece of divine workmanship should not perish, something ought to be said concerning it, it being the foundation of everything that we have hitherto been treating of, since without copulation there can be no generation. Seeing, therefore, so much depends upon it, I have thought it necessary, before concluding the first book, to give such directions to both sexes, for the performance of that act, as may appear efficacious to the end for which nature designed it, but it will be done with such caution as not to offend the chastest ear, nor to put the fair sex to the blush when they read it.