74 



Scientific Proceedings (80). 



37° C. and 8° C, the subsequent incubation after addition of 

 sensitized erythrocytes being carried out at the higher temperature. 



Upon known syphilitics, the cholesterinized antigen at 8° C. 

 gave the largest number of positive reactions, being followed, in 

 order of efficiency, by the plain antigen at 8° C, cholesterinized 

 antigen at 37 0 C, acetone-insoluble antigen at 8° C, the same at 

 37° C, and last the plain antigen at 37 0 C. 



Reactions considered to be false positives were obtained eight 

 times with the cholesterinized antigen at 37 0 C, five times with 

 the cholesterinized antigen at 8° C, and once with the plain 

 antigen at 8° C, in this series of 500 tests. 



47 (1225) 



On thyroidectomy in amphibia. 



By E. R. Hoskins and Margaret Morris. {By invitation.) 



[From the Department of Anatomy, N. Y. University and Bellevue 

 Hospital Medical College and Department of Zoology, Yale 



University.] 



With due care to technique it was possible to remove success- 

 fully the anlage of the thyroid gland from young growing larvae of 

 R. sylvatica and Amblystoma punctatum. The stage best suited 

 for this experiment is that just preceding the beginning of the 

 circulation of the blood. At this time there is no danger of hemor- 

 rhage and the chances of regeneration of the removed gland are 

 fewer than with younger larvae. Chlorotone in salt solution was 

 used to produce anesthesia. 



Thyroidectomy was performed in 40 frog larvae and so Ambly- 

 stoma larvae checked against an equal number of control animals. 



A few of the thyroidectomized frog larvae developed abnormally 

 shaped external gills in some of which no circulation was to be 

 seen. This was evidently due to injury to the vascular system. 

 One animal developed no external gills although it lived and grew 

 through the period during which external gills normally persist. 



The operated animals grew less rapidly than the controls. 

 Only one control and one experimental animal survived the normal 



