198 The Philippine Journal of Science me 



The absence of the two kidneys, though embryologically in- 

 teresting, lacks the clinical importance of the unilateral cases, 

 owing to the fact that it is incompatible with life. 



The specimen studied in the present case was an apparently 

 normally developed embryo in no outward point different from 

 the others of the same litter. 



There are apparently no other abnormalities found in the 

 rest of the urinary apparatus aside from the absence of both 

 kidneys and the short and maldeveloped left ureter. Both 

 ureters were normally placed, and both ended in expanded ex- 

 tremities, which were lost in the surrounding fascia. 



The genital tract appeared normal as compared with embryos 

 of approximately the same size. 



The adrenals were larger than normal and appeared rather 

 advanced in differentiation. 



There were no traces of tissues in the region of the nephro- 

 genic cord, which on microscopic study might suggest the least 

 appearance of renal blastema. The four or five glandular 

 collections, which might be regarded as suspicious, were dem- 

 onstrated to be lymphoid bodies and masses of mesenchymatous 

 tissue without signs of tubular formation whatsoever. 



From the present case the following conclusions may be 

 drawn: 



1. In the case of the right ureter the absence of kidney is 

 probably due to a failure of the nephrogenic blastemal cap to 

 appear or to develop, the upper expanded end of this ureter 

 having undergone tubular divisions preparatory to the forma- 

 tion of the medulla of the kidney. 



2. The left ureter may have been arrested in its growth 

 cephalad and become entangled with the mesenchyma of the 

 pelvis, thus failing to reach the nephrogenic cord and meeting 

 the blastemal substance which might have existed and under- 

 gone regression. 



3. From the apparently normal development in general of 

 this specimen as compared with the others of the same litter 

 it is probable that kidneys are not essential for proper growth 

 intra utero. 



4. The adrenals said to be generally larger in renal absence 

 as reported by Coen and others is also confirmed in this specimen. 



This work has been done under the immediate supervision of 

 Dr. E. S. Ruth, to whom I wish to express my sincere thanks 

 for kind and very helpful suggestions. I also wish to thank 

 Dr. B. C. Crowell for valuable help in the microscopical study 

 of the sections. 



