872 JOHN R. WILLIAMS 



being replaced by a confused image. This type is seen in some tumors 

 and especially in inflammatory lesions as meningitis and syphilis which 

 include in their mass the surrounding brain tissue, (f) A less frequent 

 form is one in which the sella is of normal size or smaller than normal. 

 There appears to be a bony bridge binding the anterior with the posterior 

 clinoidal processes. This bony anomaly causes pressure on the infundib- 

 ulum, the posterior lobe and base of the brain, producing diabetes in- 

 sipidus. 



Gushing attaches value to sellar X-ray examinations, particularly in 

 long standing tumor cases. 



In a recent study of the sellse of one hundred normal individuals by 

 this method, Jewett found quite marked variations in size and shape. The 

 individuals examined represented all ages and variations in weight and 

 stature and these seemed to be factors having to do with the shape of 

 the sellse. Jewett classified his findings into eight groups which repre- 

 sent nearly every variety observed by Maraiion. In the light of present 

 accomplishment, X-ray evidence in the study of the majority of cases of 

 diabetes insipidus must be regarded as of uncertain value. 



Pathological Anatomy 



As has been indicated, most of the workers in this field, led by Frank 

 and Gushing, have believed that diabetes insipidus is due in most instances 

 to a lesion of the hypophysis. According to Camus and Roussy, this 

 organ has little to do with it. In a series of experiments on dogs, they 

 showed that when the hypophysis alone was injured, polyuria did not 

 result. But when the brain area about the infundibulum, forward to the 

 optic chiasm and posterior to the level of the gray substance in the tuber 

 cinereum, was stimulated or damaged, polyuria promptly followed (see 

 Figures 5 and 6). They state with emphasis that the lesion which 

 determines polyuria in no way concerns the pituitary body. The depth 

 of the injury has nothing to do with the intensity of the polyuria, a super- 

 ficial lesion being sufficient to produce the phenomenon. In their experi- 

 ments, the polyuria appeared to precede the thirst and they are definitely of 

 the opinion that the latter is merely a consequence of the former. Leschke 

 also believes that the hypophysis is not concerned in the production of 

 the syndrome and that when a tumor in this organ does cause polyuria, 

 it is because it presses upon the tuber cinereum. In basal meningitis 

 when polyuria is observed, the hypophysis may not be involved. If the 

 pituitary alone is destroyed by disease, polyuria is never observed. Hous- 

 say reaches similar conclusions as to the brain areas involved in the pro- 

 duction of the syndrome. Gushing, on the other hand, believes that some 

 cases at least occur in pituitary insufficiency, basing his conclusion partly 



