Scientific Proceedings. 



45 



killed in order to determine whether metastasis from the first 

 inoculation had taken place. The results of this series of experi- 

 ments show that secondary inoculation succeeds in a high per- 

 centage of the rats in which no visible metastases can be seen, and 

 in which visible metastases, in the lungs chiefly, are present. The 

 exact figures will be given in the complete publication to be issued 

 soon. 



The results of this series of experiments bear upon the view 

 expressed by Sticker, that a primary tumor protects the body 

 from the development of a secondary tumor until the period of 

 metastasis arrives, and upon Ehrlich's negative results in secondary 

 transplantations of a rapidly growing mouse carcinoma. The 

 sarcoma of our experiments is characterized by its infiltrative 

 growth, but it increases far less rapidly than the most active of 

 Ehrlich's tumors, and reaches, in relation to the size of the rat, 

 no such large size as the latter does in proportion to the size of 

 the mouse. 



34 (177) 



On certain chemical complementary substances. 

 By HIDEYO NOGUCHI. 



\From the Rockefeller Institute for Medical Research^ 



In blood serum there is a constituent known as complement 

 or alexin, which dissolves blood corpuscles or bacteria when the 

 latter are properly sensitized. Its existence can only be demon- 

 strated by the aid of immune bodies or amboceptors. The action 

 of complement disappears when the serum gets old or is heated 

 to 56 0 C. for a short time. The fate of complement after inactiva- 

 tion is not known. Complement is generally believed to undergo 

 disintegration. Blood serum yields upon warm alcoholic extraction 

 a substance or a group of substances of powerful lytic activity. The 

 same is also true of leucocytes, glands and certain visceral 

 organs. On account of some differences existing in the lytic 

 mechanism and thermal resistance between genuine serum comple- 

 ment and alcoholic " extract lysins," no direct comparison has 

 been made to establish a possible relationship between these two 

 constituents. Complement is lytic only in the presence of immune 



