42 R. G. HOSKmS 



be given a series of injections of spermatozoa its serum acquires the 

 power of destroying such cells without greatly affecting other kinds. 

 Efforts have been made to induce a similar cytolytic power for hormone- 

 producing cells as, for instance, those of the thyroid gland. Such a 

 serum might then be injected into an experimental animal or a patient 

 and cause disintegration of the thyroid tissue in situ. The method has 

 not as yet proved entirely satisfactory. The cytolytic sera produced have 

 not been sufficiently specific in action, and have destroyed other tissues 

 in addition to those at which the experiment was aimed. The method 

 is being further developed, especially by the Japanese investigators, at 

 the present time. If the experimental difficulties could be surmounted the 

 method would adapt itself almost ideally to numerous investigations and 

 as a substitute for surgery in clinical practice. 



Clinical Studies. Many of the most significant data regarding hor^ 

 mone deficiencies have been derived from careful study of patients suffer- 

 ing from endocrin gland defects. Addison's discovery that deficiency of 

 the suprarenal glands results in muscular and circulatory weakness re- 

 mains as probably the most significant information yet offered bearing 

 upon the physiology of these glands. Scarcely less significant has been 

 the discovery of the relation of the thyroid glands to myxedema and 

 cretinism. The relation of the gonads to the development of secondary 

 sex characteristics has been familiar knowledge from earliest times through 

 observations of eunuchs. 



In cases of frank primary deficiency of some one endocrin organ the 

 problem is relatively simple. But as it presents itself clinically the 

 problem is very frequently complicated by the possibility of interrela- 

 tions among the various glands. A given cause may act simultaneously 

 on several members of a related congeries of organs producing a hyper- 

 trophy due to overfunction in each. But a hypertrophy- of one of a 

 related pair may also be due to the vicarious assumption of the function 

 of the other. This is a common interpretation of the pituitary hyper- 

 trophy which follows thyroidectomy. When one organ normally exer- 

 cises a check upon another, hypertrophy of the second may result from a 

 depression of the activity of the first. If, on the other hand, one organ 

 normally stimulates the other, as the thyroid does the suprarenal, hyper- 

 trophy in the second may he due to overactivity in the first. In view of 

 these different possibilities of interpretation to determine in case of any 

 observed clinical phenomenon its actual cause is frequently difficult or 

 impossible. 



Moreover, primary and secondary causes may be inextricably mingled. 

 Tn the latter case various ohsciire pluriglandular syndromes may arise. 

 The indefiniteness of the phenomena observable in such cases has led to 

 much speculation and premature theorizing, which have, to a considerable 

 extent, cast discredit upon the recorded data themselves. The plurigland- 



