119 



between the results of the authors mentioned above miglit 

 be due to the fact that some worked witli intact and some 

 with stirred yolk. 



Specific Differences, Bialaszewicz (1912) 

 found - 0.444°, - 0.446° and - 0.455° for the freezing points 

 of the ovarian eggs of, respectively, Rana fuf^ca, Bana 

 escidenfa and Bomhinaior igneiis. 



Atkins (1909a) gives -0.454°, -0.452° and -0.420° as 

 the freezing points of the eggs of the chicken, the dnck and 

 the goose. 



I n cl i V i d n a 1 Differences. The last mentioned 

 author reported a difference of 0.05 degree between the 

 extremes of 12 lien's eggs and 0.09 degree between the 

 extremes of 7 dnck eggs. 



Moran (1925) observed individual differences of the 

 same order for both the white of egg and the yolk. 



Cycle in the Freezing Points of Develop- 

 ing E g g s. Atkins (1909a), investigating the difference 

 between the osmotic pressure of the blood and that of the 

 eggs, in birds, as related to the exchanges between the egg 

 and the mother's body, obtained a freezing point 0.13 

 degree lower for the blood than for the eggs. He attrib- 

 utes this fact to a higher concentration of inorganic salts 

 in the plasma of the blood, as a determination of the chlo- 

 rine content showed. 



Atkins (1909b) furthermore observed that the freezing- 

 point of the eggs drops, during incubation, by about 0.15 

 degree. The mixed content of the egg (after the separa- 

 tion of the embryo, at the end of the incubation period) 

 froze at -0.611°, that is, at nearly the same point as the 

 blood. The author suggests that the animals in the phylo- 

 genetic series might exhibit the same differences in the 

 osmotic pressure of their internal fluids as do the embry- 

 onic forms in the ontogenetic series. According to this 

 view, the birds, for example, should have body fluids of 

 lower freezing point than the reptiles from which they 

 descend. 



Bialaszewicz (1912) gives the following figures for the 



