testis

Sperm are produced in the testes and stored in an adjacent organ called the epididymis.

Part of the challenge is that for the precursor stem cells to develop into fully matured egg or sperm cells, they must be placed in an environment mimicking that of newly developing ovaries or testes.

In humans, males and females have the same set of about 60 sex-determining genes, which can create either testes or ovaries.

If fully functional, these basic components of reproduction can merge into a fertilized egg inside a test tube, be transplanted into a surrogate, and birth a new generation without ever seeing testes or ovaries.

Chimps have also evolved in the last millions of years, and the main difference between them and other ancestors seems to be with mating-related genes involving testes and sperm competition.

A moderately enlarged testis (probably regressing) was noted in the specimen from Pisté, on July 21.

Et hunc ipsa testis hæc audisse recordata est et stupefacta fuit.

Others imagine that the citron is intended, whose shape makes it an emblem of the testis.

The testis is rounded, and consists of a mass of cells, on an average 1/5000th of an inch in diameter.

The eye lies on the line of junction between the testis and the vesicula seminalis, and on their ventral side.