600 LECTURE XXVI. 



The relations of the sexual organs to the entire organism are very inter- 

 esting. By numerous experiments on men and animals, it has become 

 well recognized that extirpation, the so-called castration, before sexual 

 ripening has taken place, tends to prevent the formation of the secondary 

 sexual character. This is well illustrated in cocks, which, as we all know, 

 when fully developed sexually may be recognized by their wattles and 

 combs. These remain undeveloped, or at least are but scanty, if the testes 

 are removed before the sexual development is complete. It is interesting 

 also to find that a secondary sexual character develops if the extirpated 

 testes are transplanted after their removal from the fowl. 1 



One of the most prominent results of the removal of the sexual glands 

 is an abnormal growth of the bones. In castrates it is frequently found 

 that especially the tibia and the femur are prolonged. The cause of this 

 has been traced to a faulty ossification of the epiphysis cartilage such that 

 there is no limit placed upon the growth of the bone. Apparently castra- 

 tion affects the general metabolism. The great tendency of castrates 

 towards obesity is well known. It has never been positively established 

 whether this results primarily from the loss of the sexual glands or whether 

 it is a secondary effect. 



Although there is undoubtedly a connection between the sexual organs 

 and the other organs of the body, still at present we are unable to identify 

 any definite product of their secretion as the active principle. We know 

 of glands, however, which are ductless, but do not give rise to such 

 secretions. We refer to the suprarenal bodies and the thyroid gland. 



The extirpation of the two suprarenal capsules has been made by Brown- 

 Sequard, 2 whom we have to thank for many investigations in this line of 

 research. He found that their removal caused death in a short time. He 

 was able to keep the animal alive, if a part of one of the capsules was allowed 

 to remain. The animal soon lost in weight and showed a peculiar behavior. 

 It was lazy, and if compelled to work soon became very tired. One 

 of the pronounced effects was that the blood-pressure fell immediately 

 after the operation. The fact that the blood from such animals had toxic 

 properties, and when injected into normal animals led to similar symp- 

 toms, as in the animal which had undergone the operation, gave rise 

 to the assumption that the suprarenal capsules served to destroy those 

 products formed by metabolism which are injurious. According to this 

 view, the suprarenal bodies serve merely as a means of protection. There 

 is no conclusive proof of the correctness of this assumption. It is clear 

 that the extirpation of these capsules may influence metabolism in such 

 a way that when they are removed from the body some product circu- 

 lates through the body in an abnormal condition, and the toxic properties 



1 Foges: Pfliiger's Arch. 93, 39 (1903). 



2 Compt. rend. 43, 422 and 542 (1856) ; ibid. 45, 1036 (1857). 



