Gubernaculum comes directly from Latin gubernaculum, helm or rudder, which is derived from the verb gubernare, to steer.
The port gubernaculum of an ancient Greek boat. The helmsman (yes, the gubernator) is controlling the starboard one as well.
from the Dictionary of Greek and Roman Antiquities, 3rd Edition by Anthony Rich. 1874
The gubernacula are the cords of connective tissue once thought to actively guide the descent of the fetal testes from the posterior abdominal wall into the scrotum during the last months of development. Although they are often described as fibrous cords with the implication of being tough supporting structures, they are in fact composed of soft mesenchymal tissue and probably "govern" the testicular descent passively by providing paths of least resistance (although in mice there is evidence that components the cords may contract in response to hormonal stimulation towards the end of the descent, hastening the entry of the testes into the scrotal sac).
The ovaries descend in the female as well, stopping in the pelvic cavity, and a homologous gubernaculum is also present. The more superior portion of the female gubernaculum develops into the ovary's suspensory ligament, and the inferior part, the ovarian ligament, which attaches the ovary to the uterus, and, a bit ironically, prevents further descent. The gubernaculum in the male turns into the gubernaculum testis, a ligament that attaches the testis to the floor of the scrotum.
Also derived from gubernare are the words gubernatorial and governor.