_Scrotum._—The main generative glands in the male, the testicles, are situated within a bag, the so-called scrotum, outside of the abdominal cavity. This bag or pouch, hanging between the thighs, below the symphysis, consists of two compartments which are separated by the septum scroti. The scrotum may be considered as a diverticle of the anterior abdominal wall. Before the descent of the testicles from the abdominal cavity, two diverticles of the abdominal wall are formed, at two points anteriorly to the genital swelling, where later on the inguinal canals are found. The diverticles extend to the swelling and coalesce to form the bag. The raphe, or last, at the point of their union, can be observed through the entire life of the individual. This median raphe runs from the perineum to the penis, indicating the inner division of the scrotum. The scrotum being a derivative of the abdominal wall, it follows that its wall will consist of the same elements as the abdominal wall. The first layer of the abdominal wall, the epidermis or cutis, forms also the epidermis of the scrotum. The fascia superficialis abdominis constitutes the second layer of the scrotum, or the tunica dartos. The musculus obliquus abdominis externus goes to make up the third layer, the so-called Cooper’s fascia. The musculus obliquus abdominis internus forms the fourth layer, or the musculus cremaster externus. The musculus transversalis abdominis furnishes the cremaster internus muscle, and the tunica vaginalis communis, or the fifth layer. Finally, the double layer of the abdominal peritoneum forms the tunica vaginalis propria of the scrotum. Between the two lamina of this tunica is found some fluid which, when pathologically increased, constitutes the anomaly called hydrocele. _Testicle._—The testicle is an ovoid organ with two surfaces, a median and lateral, with two poles, an upper and lower pole, and two margins, an anterior convex and a posterior straight margin. In the natural position, the upper pole is somewhat anteriorly inclined. The average weight of the testicle is 15 to 25 grammes, average length 5 centimeters, breadth 2 to 5 centimeters and thickness 3 centimeters. The superior pole and the posterior margin of the testicle are covered by the epididymis. The left testicle, as a rule, hangs deeper than the right.