HYDROLYSIS OF HIGHER FATS IN EGG-SECRETION. 69 



changes localized at the oil-exudate interface. Here important 

 disturbances should take place, although mere volumetric changes 

 are not likely to be reliable. The diffusion of the glycerine set 

 free in hydrolysis would, of course, result in a decrease in the 

 volume of the oil drops. On the other hand, the production of 

 oleic acid with its great affinity for oxygen and its capacity for 

 breaking down into lower fatty acids might easily balance, or even 

 overbalance, the loss resulting from the solubility of the glycerine 

 in egg-water. Conceivably, then, the drops might decrease in 

 volume, increase in volume, or even remain constant. 



Nevertheless, if hydrolysis takes place, a lowering of the surface 

 tension at the oil-exudate interface is to be expected, and, regard- 

 less of volumetric considerations, should bring about a concentra- 

 tion at the phase-boundary of substances either in solution or in 

 suspension within the oil. If such substances happen to be in- 

 soluble in egg-secretion, one may likewise expect their precipitation 

 immediately about the periphery of a drop from which glycerine 

 and possibly the oxidation products of oleic acid, are diffusing 

 outward. 



I used two indicators; in some tests Sudan III. was dissolved in 

 the olive oil, in others pulverized charcoal was suspended. A 

 sharp phase-boundary, permitting a clear focus under the micro- 

 scope, was secured by placing small discs of the oil on the surface 

 of the exudate. The observations were checked by comparisons 

 made on sea-water and distilled, as well as by the use of oil with- 

 out indicators. Additional controls were carried on with solutions 

 of pancreatin and the commercial Holadin. 



With discs of plain olive oil on sea-water, there is some marginal 

 effect. This is indicated by the rather rapid development of a 

 moderately irregular outline. On distilled water the discs maintain 

 their smooth circular form almost perfectly during the first few 

 hours of an experiment. The differences in these two cases are 

 no doubt traceable to the sea salts. 



If egg-secretion is used in place of sea-water, the oil discs in 

 the course of an hour take on a form suggestive of a circular saw 

 whose projecting teeth are in a state of active disintegration. 

 Small particles can be seen breaking off in large numbers until the 

 originally sharp outline of the disc becomes quite obscured. Simi- 



