YOU HAVE MIXED FEELINGS about me. For instance, you respect me as proof of your maleness. But then, you are vaguely ashamed of me. I vigorously reject this attitude. I am quite as respectable as any organ in your body, and far more remarkable than most. But for me and my kind, neither you nor anyone else would be here.
Nature is wiser than you in, estimating my importance. Mostly, you have one gland of a kind. There are two of me. You think of me as related only to sex, but I do chemical conversions that would amaze you. It was I who changed you from a boy to a man; and, to a great degree, it is I who will decide if your old age will be tranquil or miserable.
I am your left testis. Compared to other glands, I am not bad looking at all: a glistening, pink-white oval. I weigh half an ounce and am 1 1/2 inches long, three quarters of an inch at my greatest diameter. My function is dual: to manufacture those creators of life, the sperm cells; and to produce the hormone of maleness, testosterone. This chemical assists in construction of muscle, bone and other tissues. It helps shape your mental attitudes as well as your body. But for it, Joe would be soft, flabby, beardless, and apathetic.
I am a very complex piece of machinery. Few parts of your body do so much of importance in so small a compass. I contain a thousand tubes, each of them one or two feet long - roughly a third of a mile of them, all as fine as the finest sewing silk. These, in turn, empty into a large collecting tube, 20 feet long. It is in this duct system that I manufacture 5O million sperm cells a day. This means that every four months I produce cells that have the potential of populating the entire earth.
Of this vast number, only those that produce/d your children have played out their role. Why such an extravagant excess? It is a dim reminder of life's origin in the seas. Some fish simply spray sperm into the water on the off chance that a drifting egg will become fertilized.
In addition to my duct system, I contain millions of Leydig cells. These are the producers of my testosterone. Curiously, this manhood chemical is also found in women who have about 1/20 your amount circulating in their blood, produced by their adrenal glands. Without it they might be frigid. With too much they would likely be masculinized.
When you were in your mother's womb, my partner and I were inside your body. Two months before birth, we descended to our present position through a little opening called the inguinal canal. Later, this can be a danger spot for hernia, if the canal doesn't completely close off after the testes have descended.
Had we failed to descend, you would have been sterile - and for a very interesting reason. Your normal body temperature is 98.6 degrees. At that level I cannot produce viable sperm. I must be held at a temperature three degrees lower than the rest of your body. To achieve this, I have an elaborate air-conditioning system. The sac which holds me is rich with sweat glands, which cool by evaporation of moisture. Also, as you have noticed, in a Turkish bath I drop down. In an effort to keep me cool, the cord that suspends me has lengthened. In a cold shower it shortens, pulling me close to the body for warmth. Anything that interferes with this temperature control influences my sperm production. If you were to move to the tropics, it would fall; in the Arctic it would rise, since cold stimulates me.You once ran a fever for a week. You didn't know it, but I ceased sperm production, and you became temporarily sterile.