INTERRELATIONS 397 



In the present chapter no attempt will be made to cover the 

 field just indicated ; it will be necessary to confine our atten- 

 tion to the known or reasonably suspected instances of influ- 

 ences exerted by one internally secreting gland upon others 

 of the series, these influences being not always necessarily 

 direct as, for example, when the nervous system is called 

 into play. 



If there has been in many instances undue haste in formu- 

 lating theories of the functions of individual glands, much more 

 has this been the case in regard to theories of interrelationships . 

 It is not certain that the clinicians have been greater offenders 

 than the laboratory workers, though it must be confessed that 

 many of the descriptions of syndromata which have been 

 supposed to accrue from correlated disturbances of the endo- 

 crinous organs are based upon an inadequate conception of the 

 actual physiological facts and therefore form a very unsatis- 

 factory indication for treatment. 



A priori and regarding the question chiefly from the morpho- 

 logical standpoint, it is doubtful if one would expect the 

 various ductless glands to be related to each other. From a 

 broadly comparative standpoint, it is very difficult to arrange 

 these glands in a coherent series. There are reasons, fully 

 explained elsewhere (p. 227 et seq), for regarding the thyroid, 

 parathyroids and thymus (along with certain less important 

 branchial cleft organs), as morphologically related. Some 

 authors regard the thymus as closely related to the thyroids 

 and parathyroids from a physiological as well as a morpho- 

 logical standpoint. The glandular portions of the pituitary 

 body may possibly be included in this morphological group, 

 but it must be pointed out that the origin of these different 

 organs is not quite identical. The only common feature is 

 that they arise from some part of the primitive alimentary 

 canal or its vascular outgrowths, the gill clefts. The pituitary 

 body arises from the ectoderm, while the branchial cleft organs 

 are of entodermal origin. 



The cortex of the adrenal body is a representative of a kind 

 of tissue which is widely distributed in the region of the repro- 

 ductive organs (see p. 116), and possibly it might be expected 

 that the corpus luteum and the interstitial cells (as well as the 

 rest of the elements) of the ovary and the testis might rank in 

 the same group. 



