A vein and artery descend from the left emulgents into the testis of the left side. They are the seminal passages swollen with blood and spirit; the seminal matter contained in them procreates females, because their humour is watery and requires coction. Seminal passages, likewise an artery and vein, are extended downward from the right [emulgents] into the right testis; but having arisen from the trunks of the vena cava and aorta artery, therefore the juice in them is less watery, and properly concocted is more suited for the generation of males. In these passages blood is concocted, and afterward transferred to the glandular flesh of the testes it acquires the form of semen.[20] The kidneys are solid and hard organs, not sentient, and the attractive force in them is very powerful. They purge the blood of its watery part and bile, but they retain [some of] the blood so that they may be nourished by it and expel the rest of the humour. For the OURĒTĒRES are attached to them,[21] that is, the urinary passages, whitish, reed-like and tensile which it may be said extend to the bladder and are similar to its substance. The diaphragm is a membranous substance, running between the vital and natural members. It is called DIAPHRAGMA by the Greeks. It strengthens the expulsive force in the intestines, it is assigned to the members selected for spirit, and it curbs the smoky vapours lest they blacken the vigorous spirits of the heart and brain. Above, there is affixed to it a sinewy covering[22] which clothes the thorax inwardly and binds the pectoral ribs to the interstitial spaces, which covering the Greeks in good part name PLEURA, but sometimes it is called HYPOZŌMA[23] by them. By its inflammation pleurisy occurs, the name taken from the covering.