DEPARTMENT OF EMBRYOLOGY. 89 



ammonium citrate was given alone, it was found that ferric iron did not reach 

 the tissues of the fetus. It was only where a very large dose was administered 

 that there was a questionable trace of iron found in the fetal urine. As a 

 final precaution, the factor of anesthesia was taken into account and it was 

 found that where urethane was used the results were the the same as under 

 ether anesthesia and in decerebrate animals. From Dr. Cunningham's work 

 it seems clear that in the placenta we have a regulating mechanism which is 

 capable of controlling at least the passage of iron-containing substances, the 

 decomposition of which is necessary for their preparation for fetal use. 



With the purpose of obtaining more precise knowledge concerning the 

 functions of the fetal membranes in the developing egg of the hen, Dr. G. B. 

 Wislocki injected with trypan blue a large number of eggs of 11 days' incuba- 

 tion, orienting his injecting needle so that each of the various compartments 

 was sure to be reached in a certain number of eggs. On the thirteenth day the 

 eggs were examined and the effect of the dye on the different structures was 

 observed. When placed in the yolk-sac the dye was taken up by the lining 

 epithelium, particularly in the region of the area vasculosa, and, penetrating 

 the basement membrane, reached its final destination, the groups of cells 

 surrounding the vessels of the yolk-sac wall. The endothelium lining the 

 vessels remained unstained and none of the dye reached the embryo, not even 

 through the yolk-stalk into the intestine. When trypan blue was injected 

 into the allantoic sac it colored the allantoic fluid uniformly dark blue, but was 

 not taken up by the wall of the sac, nor did any of it reach the embryo or its 

 other membranes. This accords well with the view that the allantois serves 

 only as a reservoir for excretory products. When injected into the amniotic 

 sac the dye was taken up by the amniotic membrane and was found in the 

 stomach, intestines, trachea, and primary bonchi, indicating that the amniotic 

 fluid is swallowed by the embryo. When trypan blue was injected into the 

 mesoblastic tissue, vital staining of nearly all parts of the embryo occurred. 

 It was found in greatest abundance in the Wolffian bodies, in the form of 

 fine granules in the epithelium fining the uriniferous tubules. Evidently, this 

 is the main pathway of excretion at this period. The next in order of abun- 

 dance of dye was the liver, where the granules were found in nearly all of the 

 endothelial cells lining the sinusoids and the terminal branches of the portal 

 vein. There was none in the fiver-cells. The dye was found in small amounts 

 in the cells lining the vascular channels of the spleen and in the mononuclear 

 cells of the splenic sinuses. Except in these three organs, it was encountered 

 only in traces, and not infrequently in the connective tissue, in cells resembling 

 clasmatocytes. 



Uterine Ciliation. 



A description has heretofore been given of the studies of Dr. G. W. Corner 

 on the changes in the mammalian ovary and uterus during the successive 

 events of the reproductive cycle. With the familiarity thus acquired of 

 cyclic changes in the uterine endometrium, it has been possible for Dr. Corner 

 and Mr. F. F. Snyder to make an important contribution regarding uterine 

 ciliation, which serves to prove its non-correlation with the time of ovulation 

 and the wandering of the ova. They have been able to show that cilia are 

 not present on the surface epithelium of the uterus of the pig at any period of 



