264 
ZOOLOGY: H. E. JORDAN 
pseudoglobulin in the unheated and heated serum divided by the amount 
of pseudoglobulin in the unheated serum gives the percent transformed; 
these are tabulated at the bottom of table 2. Thus for Anthrax 48, 
the figures are (0.290-0.211)/0.290 = 27%. This is not the only way 
to calculate this figure. Figures for pseudoglobulin may be obtained 
from a different set of results; thus, they may be calculated by sub- 
tracting the figures for albumin (e) from those or pseudoglobulin plus 
albumin (c) . If the percent of transformation be calculated from these 
lower values for pseudoglobulin the figures are, 24, 8.4., —1.2, 12.4 
and 11.2%; to read across the bottom of table 2. 
Further details are given in the Journal of Agricultural Research^ 1917. 
1 Banzhaf, E. J., Proc. Soc. Exp. Biol. Med., 6, 1908, (8). Also, in Collected Studies 
from the Bureau of Laboratories, Department of Health, City of New York, 7, 1912-1913 
(114), and 8, 1914-1915, (209). 
» Eichhom, A., Berg, W. N., and Kelser, R. A., /. Agric. Res., 8, 1917, (37). 
A CASE OF NORMAL EMBRYONIC ATRESIA OF THE ESOPHAGUS 
By H. E. Jordan 
DEPARTMENT OF ANATOMY. UNIVEI^ITY OF VIRGINIA 
Communicated by A. G. Mayer, January 20, 191 7 
In a series of loggerhead turtle embryos, collected and used originally 
for a study of the history of the primordial germ cells, the esophagus 
was observed to be solid for a greater or less extent, approximately 
from the point of origin of the respiratory anlage to its bifurcation into 
the bronchi, from the twelfth to the thirty-second day of incubation. 
At the latter stage the esophagus is still occluded at its oral end, though 
now fenestrated for a considerable extent caudally; and it seems prob- 
able that the esophageal atresia persists practically to near the end 
of the incubation period (eight weeks) at the level just behind the open- 
ing of the larynx. 
The points of special significance in regard to this material are: (1) 
the relatively longer persistence of the occlusion than has yet been 
described for any other form; (2) the absence of contributory yolk in 
the stenosed area; and (3) close relation of the atresia to the point of 
origin of the respiratory anlage, which fact may disclose its possible 
functional significance. 
Balfour^ was the first to describe a similar phenomenon in the 
esophagus of certain selachii. Kreuter^' ^ confirmed these observa- 
tions in the case of Pristiurus and Torpedo. Dean* reports a solid 
esophagus in larvae of Amia calva. An occluded esophagus is said to 
occur also in certain bony fishes, e.g., herring, trout, salmon (Balfour; 
