418 
RUTH RAND ATTERBURY 
ureteric epithelium in the allantois, the formation of the collecting 
tubules in the grafts does not differ from that usually described 
for their normal development within the organism. 
On the other hand, the study of the ureteric epithelium in the 
allantois reveals in it a potency which is not exhibited under 
normal conditions, i.e., a phagocytic digestive capacity. As 
might be expected, extirpation of the metanephric anlage from 
Text figure B Camera-lucida drawing to illustrate phagocytic activity of 
ureteric epithelium against degenerating red corpuscles. Metanephric graft of 
three days’ growth. B.C., Bowman’s capsule; c., capillary; D.E., degenerating 
erythrocytes; G, developing glomerulus; I.E., ingested erythrocyte; I. Hb-c., 
ingested hemoglobin-containing particle; N.T., nephrogenous tissue; U.T., 
large collecting tubules. 
the body cavity of the embryo is usually accompanied by hemor¬ 
rhage. It is not uncommon, therefore, in the grafts to find red blood 
corpuscles present in the lumen of the ureter bud. This new 
environment is apparently unfavorable for their maintenance and 
they gradually undergo degeneration. When degenerating eryth¬ 
rocytes are present within its lumen, the ureteric epithelium 
is seen to exhibit an intensive phagocytic activity. Text figure B 
