PHYSIOLOGY AND EXPERIMENTAL PATHOLOGY 731 



hypophysis to go on to full development and in which there have been no 

 evidences of tumor. 



The role which the posterior lobe plays in causing some, of the 

 symptoms observed in acromegaly and dystrophia adiposogenitalis is not 

 understood and physiological experiments have failed to throw light upon 

 this question. 



Polyuria Associated with Lesions of the Hypophysis. Experi- 

 mentally a marked polyuria may follow operative procedures upon the 

 hypophysis. The exact nature of the lesions causing such polyuria is 

 still under discussion. 



Kahler in 1886 in analyzing 22 cases of diabetes insipidus found the 

 lesion in seven of these about the infundibulum, the substantia perforata 

 posterior and the corpora mammillaria. 



In 1913 Lewis and Matthews repOTted 18 experiments relating to 

 diabetes insipidus. The hypophysis was approached through the buccal- 

 transpalatosphenoidal route. 



The following may be cited as a typical example of polyuria following 

 operative interference. 



Experiment 10. Dog weighing 4.5 kgm. was operated upon October 6, 

 1912, and killed October 12, 1912. The hypophysis was exposed and in- 

 jured by a cautery. The animal passed on 



October 6-7 2450 c.c. of urine, sp. gr. 1.000 

 October 7-8 3900 c.c. of urine, sp, gr. 1.000 

 October 8-9 900 c.c. of urine, sp. gr. 1.007 

 October 9-10 300 c.c. of urine, sp. gr. 1.012 



In this case the anterior lobe of the hypophysis was injured. Eighteen 

 animals were operated upon. Nine developed polyuria after the opera- 

 tion and nine did not. In an animal which developed the most marked 

 polyuria, passing 5000 c.c. of urine during the first 24 hours, a large 

 amount of pars intermedia was found in the specimen. The cells of this 

 remnant took, however, a much heavier stain than normally. 



In all of the nine specimens removed from animals which had marked 

 polyuria, distinct remnants of pars intermedia which appeared to be in 

 good condition were found. Remnants of pars intermedia were found in 4 

 animals which had no polyuria. In one of these there were distinct evi- 

 dences of a marked inflammatory reaction about the pars intermedia and 

 the animal presented general symptoms from the beginning, which un- 

 doubtedly would have abolished or modified a polyuria. In two other 

 cases in this group the remnants of the pars intermedia were badly dam- 

 aged, being surrounded by a fairly large blood clot. In one the remnant 

 of pars intermedia was in good condition and it would have been judged 

 from a histologic examination that the animal from which this specimen 

 was removed might have had polyuria. 



