22 A. J. GOLDFARB. 



urged by Child, or to the greater accumulation of metabolic 

 toxic products as urged by Loeb, or to both of these factors, we 

 cannot in our present state of knowledge determine. 



SUMMARY. 



Aging eggs show progressive measurable morphologic and 

 physiologic changes. Besides those described in Study II., 

 there are a number particularly evident in later stages of aging 

 eggs, such as agglutination and fusion of eggs, irregular cleavage, 

 separation of the blastomeres and cytolysis. 



A. i. The agglutination phenomenon occurred only in 

 physiologically very deteriorated or "aged" eggs, as evidenced 

 in part by the low per cent, of the jelly layer, inability to develop 

 a fertilization membrane, a more viscous condition of the cy- 

 toplasm and cortical layer, and by numerous other tests. These 

 are exactly the conditions that have been sought in the experi- 

 mental agglutination of eggs. 



2. The onset of agglutination occurred at different ages for 

 the eggs of different females, such variations being due to differ- 

 ences in physiologic condition of the eggs at the time of liberation 

 from the parent. The more deteriorated the eggs at liberation 

 the earlier the agglutination, and vice versa. Agglutination 

 occurred in every experiment in which the eggs had aged suffi- 

 ciently. 



3. Some eggs remained agglutinated throughout their subse- 

 quent developmental history, others were secondarily separated 

 at varying swimming stages in development, others died pre- 

 cociously, due to asphyxiation. 



4. Fertilized as well as unfertilized eggs were agglutinated. 



5. Clusters of 2 to 40 or more eggs were thus agglutinated. 



6. Agglutination is not determined by the condition of the 

 sperm except in so far as concentrated fresh sperm may, by 

 revolving the eggs, separate agglutinated eggs or prevent their so 

 doing. 



B. I. When the eggs were in sufficiently poor physiological 

 condition, as determined by suitable tests, they tended not merely 

 to agglutinate but many subsequently fused more or less com- 

 pletely. 



