496 ALVALYN E. WOODWARD 



xanthoproteic test, however, which indicates the presence of 

 tyrosine, phenylalanine, or tryptophane. 



3. That two substances can be precipitated from the same 

 secretion : 



a. By saturation with (NH4)2S04, a sperm agglutinin is 

 thrown down. 



h. By a method of Robertson and others, using BaCU and 

 acetone, a parthenogenetic agent is obtained. 



In an attempt to learn whether or not enzymes are present, it 

 was found that the agglutinin resembles an enzyme in the 

 effect upon it of x-radiation. It also follows the law of Schlitz 

 and Borissow, i.e., rate of action = KVC ferment. The secre- 

 tion does not give a positive reaction to tests for oxidase, cata- 

 lase, or a proteolytic enzyme. Since the. parthenogenetic agent 

 dissolves a fat obtained from the eggs, it may contain a lipase. 

 Hence it was called, provisionally, a lipolysin. 



A study of methods of inhibiting the initiation of cleavage 

 brought out that both autoparthenogenesis and sperm fertiliza- 

 tion are inhibited by: 



1 Asterias and Arbacia serum, which may, like mammalian 

 seia contain antiferments specifically protecting the cells of the 

 organism itself. 



2. 'Purple x' and 'Salmon x,' substances obtained by boiling 

 the testicular or ovarian tissues of Arbacia and Asterias. 



3. Antifertilizin, obtained from eggs which have been freed 

 from fertilizin. This inhibitor may be identical with 



4. An unsaturated fatty acid obtained by extracting the eggs 

 with ether. 



Parthenogenetic agents fall into three classes: 1) The fat 

 solvents, including lipolysin, ether, chloroform, butyric acid, etc. 

 2) The halogen compounds — iodine and various salts. 3) Physi- 

 cal methods, which may change the physical or quantitative 

 relations of substances within the egg. Not only do these agents 

 produce development in normal, uninseminated eggs, but they 

 change resistant Asterias and Arbacia eggs so that they may be 

 fertilized. 



