In consequence of an arrest of development, the cavity of the tunica vaginalis may remain in communication with the peritoneal cavity, and thus give rise to congenital inguinal hernia.

All the diseases affecting the tissue of serous membranes are found to occur here; inflammatory affections of every degree and variety, followed by the most various effusions, are common; and of the sequelae, adhesion by means of various tissues of new formation, and ossification of the fibroid exudations, are not unfrequent. Among the morbid growths we notice the anomalous fibroid and osseous tissues in the form just mentioned, as well as subserous, fibrocartilaginous, and osteoid formations, which we sometimes find as free corpuscles in the tunica vaginalis, and tubercle, occurring especially as tubercular exudation; this must be distinguished from tuberculosis of the testicle, with which, however, it is often coincident.

Dropsy of the tunica vaginalis, or hydrocele, is a common disease, occasionally brought on by varicosity and stasis in the venous network of the testicle and the spermatic cord, in which case it has the character of a passive accumulation; sometimes it is the result of slight inflammatory affections of the serous membrane.