5 o6 TEXT-BOOK OF PHYSIOLOGY 



in advanced years, with a view of reestablishing the former condition of 

 body vigor. Experiments of this character were made originally by Brown- 

 Sequard on himself and reported that his general health, his muscular power 

 and mental activity were much improved. These results have not received 

 general confirmation. 



The ovaries are also regarded as glands for the production of an internal 

 secretion, as well as for the production of characteristic reproductive ele4 

 ments. The ovary possesses in the epithelium of the Graafian follicles ail 

 apparatus for the development of the ova, and in the cells of the intervening 

 stroma the so-called interstitial cells an apparatus for the production o| 

 an internal secretion which is poured into the blood and influences not onljii 

 the development of sexual organs but influences favorably the development 

 of the secondary sexual characters as well as the body as a whole. 



The removal of the ovaries of human beings early in life is an operation 

 that is not often performed and hence it is difficult to state the results that 

 might arise. Their removal in certain animals leads to an atrophy of the! 

 uterus, and in addition, to a failure of development of secondary sexual 

 characters. Menstruation does not occur and the body does not reach matu- 

 rity. The removal of the ovaries in adult life results in a cessation of men- 

 struation, and the appearance of a variety of disorders of a body and mental 

 character. Similar phenomena are frequently observed at the menopause, 

 when the ovaries undergo degenerative changes. The administration oi 

 extracts of the ovaries oophorin tablets is claimed to relieve some of the 

 symptoms following the removal of the ovaries or occurring during the 

 menopause. The transplantation of an ovary into the wall of the uterus 01 

 into the broad ligament after ovariotomy in women has, even after the lapse 

 of two years, reestablished menstruation and awakened sexual desire. From 

 facts such as the foregoing it has come to be believed that ovaries also produce 

 an internal secretion which has a marked influence on the body and 

 mental states of women and mammals generally. 



THE SPLEEN 



The spleen is a soft bluish-red organ, oval in shape, from twelve to fifteen 

 centimeters long by eight broad and four thick. It is situated in the lefl 

 hypochondrium between the stomach and the diaphragm. In this situation 

 it is held in position by a fold of the peritoneum which passes from the uppei 

 border to the diaphragm. 



Structure. A section of the spleen shows that it consists of connective 

 tissue, blood-vessels, lymph-corpuscles, and lymphoid tissue. The surface 

 of the spleen is covered by a capsule composed of dense fibrous tissue 

 from the inner surface of which septa or trabeculae pass inward toward the 

 center of the organ. In their course they give off a series of processes which 

 unite freely, forming a spongy connective-tissue framework. The capsule 

 and the main trabeculse in some animals contain numerous non-striated 

 muscle-fibers. In man they are relatively few in number. The blood-ves- 

 sels which enter the spleen are supported by the connective-tissue septa 

 As they pass toward the center of the organ they divide very rapidly anc 

 soon diminish in size. In their course small branches are given off, whict 

 penetrate the inter-trabecular tissue and become encased with spheric 01 



