SEXUAL HYGIENE 193 



tions," are formed by the suprarenal capsules of the 

 kidney, the thyroid gland, the sexual glands, and other 

 so-called ductless glands. It is known that the removal 

 of the thyroid gland from the body of an animal will 

 produce death by the development of a peculiar form of 

 disease; but if an extract of thyroid gland, made by 

 macerating the gland in water, is injected into the 

 body of the animal from time to time, the injurious 

 effects ordinarily resulting from the removal of the 

 gland do not appear. 



More recent experiments have shown that every 

 tissue produces certain substances which, circulating 

 in the blood, modify every other tissue, thus producing 

 unity and harmony in the development of the various 

 organs of the body, independent of the nervous system, 

 thus explaining what has heretofore been one of the 

 greatest mysteries of animal physiology. 



The bearing of these discoveries upon sexual hy- 

 giene is very obvious and highly important. These 

 investigations have shown that the sexual glands are 

 useful, not only as a means of race-perpetuation, but 

 for the physical well-being of the individual, through 

 the vital stimulus exercised by them, through the influ- 

 ence of their peculiar secretion upon the processes of 

 development and nutrition. In view of this fact, it is 

 evident that, so far as the individual is concerned, phys- 

 ical benefit is to be looked for, not in the loss of the 

 secretion of the sexual glands, but in its retention and 

 appropriation. In other words, reproduction is accom- 

 plished at the sacrifice of individual interests, a law 

 which prevails throughout the whole organic world, 

 being, in some instances, so pronounced that the devel- 

 opment of progeny is accomplished only through the 

 death of one or both parents. 



