THE MALE HORMONE 



The prostate gland is one of those organs which carry on 

 their useful functions in complete silence, never making known 

 their presence or their action as long as they are in good 

 working order ; but when something goes wrong with one of 

 them it suddenly becomes the focal point of the universe for 

 the sufferer. Its bad reputation as a source of trouble in 

 elderly men is due to the fact that for some obscure reason, 

 probably of endocrine nature, the gland tends to enlarge in 

 men past 50. Situated as it is around the urinary channel 

 (see Fig. 80), and enveloped in a heavy capsule, which pre- 

 vents it from swelling outward, any marked enlargement of 

 the prostate inevitably blocks the outflow of urine, with seri- 

 ous consequences. The hope that prostatic enlargement may 

 (when we know enough about it) be brought under control by 

 treatment with hormones, lies temptingly before the investi- 

 gators and may some day be realized. 



Secondary sex characters. Before we can discuss the hor- 

 mone of the testis we must take account of certain other 

 matters that form part of the pattern of sex. Primarily a 

 male animal differs from the female, or a man from a woman, 

 because the one has in all his cells the chromosomes for 

 maleness, the other the chromosomes for femaleness. One 

 therefore develops testes, the other ovaries. The sex glands 

 then begin, even in the early embryo, to call forth the sec- 

 ondary sex characters of their respective sexes. When the 

 individual reaches the age of puberty these characters become 

 prominent. In most mammals the males are larger, and possess 

 heavier, rougher skeletons and stronger muscles. The shape 

 of the pelvis, and to a lesser extent that of the skull and the 

 other bones, is different in the two sexes. In humans the 

 anatomy of the larynx is different and therefore the voice 

 becomes either male or female. The distribution and growth 

 of the hair are different. One sex has well developed mammary 

 glands, the other only rudiments. 



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