<58 R. G. HOSKINS 



voluminous literature on organ grafting has recently been reviewed some- 

 what extensively by Mauclaire (1920). 



Nerve Stimulation. In some respects stimulation of the secretory 

 fibers to a given gland is the most satisfactory method of augmenting its 

 hormone output. The secretion thereby secured is supposedly normal in 

 quality and not greatly outside physiological units in quantity. For this 

 among other reasons a definite knowledge of the secretory innervation 

 of all the endocrin organs is needed. In case of the suprarenals and the 

 thyroid glands only is anything like satisfactory information available. 



Artificial stimulation of secretory nerves ordinarily involves a con- 

 siderable degree of trauma, as well as the use of an anesthetic, both of 

 which detract from the adequacy of the method to reproduce physiological 

 conditions. To meet this difficulty Cannon has attempted to employ the 

 method of nerve grafting, using the phrenic as a constantly active source 

 of impulses. The method is technically difficult and was abandoned by 

 Langley years ago as not feasible. Cannon succeeded in a few cases, 

 however, in obtaining results strongly suggestive, at least, of functional 

 overactivity in the thyroid gland when the central end of the phrenic 

 nerve was sutured to the peripheral end of the cervical sympathetic. 

 The resulting manifestations included, particularly, markedly augmented 

 basal metabolism. Troell and Marine attempted to repeat the work, but 

 without success. The method is theoretically an ideal one to produce pure 

 physiological augmentation of gland functions under controlled conditions. 

 The most striking advantage is that there would be no question as to 

 what is the primary cause of any effects produced, a question which always 

 arises in a baffling way when spontaneous overactivity of different endo- 

 crin glands is studied. It is greatly to be hoped that the technical diffi- 

 culties may he overcome and the method fulfill the promise it offers of 

 unraveling some of the most puzzling problems in this field of research. 



Maternal Administration. Several years ago the writer experimented 

 with a method of creating an excess. of hormones in the circulation of 

 developing fetuses by administering to the mother a corresponding giancl 

 substance, either by feeding or by injections. The method offers two 

 theoretical advantages: the experimental animal is treated at the most 

 plastic stage of its existence 1 when maximal effects would be produced, 

 and the brunt of the experimental procedure is taken by the mother, which 

 supposedly would be less likely than the young organism to suffer from 

 incidental derangements due to the gland administration. The offspring 

 ot females to which suprarenal substance was administered were found to 

 have smaller suprarenal glands than normal newborn animals of the 

 same species. This suprarenal hypoplasia was interpreted as a reaction 

 to an excess of circulating suprarenal hormones. The interpretation obvi- 

 ously assumed that olandular hyperplasia or hypoplasia may be due to 

 the operation of the chemical law of mass action, whereby a physiological 



