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Scientific Proceedings (132) 



Antigen 14. Alcoholic solution of acetone insoluble product 

 obtained from an ether extract of beef heart mixed with an alco- 

 holic extract of the same beef heart obtained as outlined in 

 Antigen 3. 



To each of the above extracts were added 400 mgm. of cho- 

 lesterin per 100 c.c. before testing with the various sera. 



The results of preliminary experiments indicate that most of 

 these antigens compare favorably with one another. In a gen- 

 eral way the acetone insoluble antigens are somewhat weaker 

 than the others. Necessarily, a large number of tests will have 

 to be carried out before establishing the degree of sensitiveness 

 and particularly the specificity of these various antigens. 



It is of interest to note that "Antigen 6" which can be prepared 

 in about three hours, appears to give unusually sensitive as well 

 as specific reactions. This as well as the other antigens outlined 

 are still being investigated and other antigens are under prepa- 

 ration. 



242 (2202) 



The elaboration and release of the colloid of the thyroid. 



By EDWARD UHLENHUTH. 



[From the Laboratories of the Rockefeller Institute for Medical 

 Research, Neiv York City.] 



The development of the thyroid of the salamander Amby stoma 

 opacnm was studied on serial sections of thyroids in various 

 stages before and after metamorphosis. 



The proportion of colloid and epithelium was found by weigh- 

 ing separately wax models of the colloid and epithelium. During 

 the larval period the colloid increases more rapidly than does the 

 epithelium. From 13 per cent., shortly after hatching, it in- 

 creases to 45 per cent, of the total thyroid mass just before 

 metamorphosis. The larval period is not a period of colloid 

 release, but of colloid elaboration and storage. At the 

 beginning of metamorphosis, the colloid percentage drops 

 suddenly below 30 per cent. This drop is due partly to the 

 sudden and excessive release and disappearance of the col- 

 loid from the follicles, and partly to an excessive increase 

 of the epithelial mass, owing to the swelling of the individual 



