XI. B, 5 Garcia: Absence of Kidneys in a Pig Embryo 193 



urachus. The two hypogastric arteries are also well defined 

 and normally located. The kidneys are absent, and no traces 

 of what might be taken for rudiments of these organs can be 

 found in the neighborhood of their normal position. The two 

 ureters are well developed, and their orifices at the trigone are 

 patent. The right ureter, which appears slightly larger and 

 longer than the left, begins from the right inferolateral side 

 of the bladder, passes in an upward and lateral direction for 

 about 9 millimeters, then continues upward in a wavy course 

 over the quadratus lumborum for about 16 millimeters, and ends 

 in a funnel-shaped expansion which is lost in the retroperitoneal 

 fascia in this region. The left ureter, slightly smaller in diameter 

 than the right, is decidedly shorter and lacks an abdominal 

 portion. Traced from the lower inner side of the bladder, it 

 passes in a lateral direction to the back of the pelvis with a 

 slight concavity upward for a distance of 6.5 millimeters and 

 ends in a thin membrane attached to the posterior pelvic wall. 



Occupying apparently normal positions, the adrenals appear 

 as two large, more or less pyramidal masses which are about 

 three times as large as those of pig embryos of approximately 

 the same size, 



Retroperitoneally, over the right quadratus lumborum, and 

 on a level with and lateral to the expanded upper end of the 

 right ureter, a small mass of glandularlike tissue of irregular 

 shape is found. This was removed, marked "G," and imbedded 

 for histological examination. Two similar bodies were seen on 

 the right lateral portion of the posterior abdominal wall, one 

 immediately above and the other to the mesial side of the right 

 ovary; both were removed for embedding and marked **I>" 

 and "H," respectively. On the left side two similar masses 

 were also seen, one of triangular shape a few millimeters lateral 

 to the left ovary, and the other oval in shape, immediately below 

 it. These were embedded as "B" and "A" respectively. No 

 other masses of tissue which might be looked upon as suspicious 

 traces of kidney were seen in this region (fig. 1). 



The abdomens of other pig embryos approximately of the same 

 size were opened and studied for comparison. 



In a pig embryo 120 millimeters in length the right kidney 

 measured 15 by 7.5 by 7 millimeters; and the left, 15.5 by 7.5 

 by 6.5 millimeters. Both were situated on the posterolateral 

 wall of the abdomen and were so prominent as to be the first 

 things noticed on lifting up the coils of the intestine. Capping 

 both organs were the two triangular adrenals which were about 

 one third as large as those found in our kidneyless specimen. The 



