Iletin and Blood Sugar 



249 



used. Very few duplicate determinations were made. Further 

 data concerning the extracts and dosages are given in the ac- 

 companying paper. 



The curves of Figure 1 show the chief results obtained on 

 ring-doves. In these very tame birds one can obtain samples 

 probably unaffected by emotional glycemia resulting from hand- 

 ling or sampling at one-hour intervals. This is not equally pos- 

 sible with common pigeons and the extent of the fall of the 

 sugar value at one hour after injection was not there measured 

 (Figure 2). But comparison of the curves of the two groups 

 clearly suggests that the maximum effect, of the lighter dosage 

 at least, is reached in less than two hours in the common pigeon 

 as is proved to be the case in the ring dove; probably this 

 limit is attained within one hour. 



FIGURE i 



ISO RING DOVES 



4 0 2 4 6 (HOURS) ft 21 



It is notable that in neither of the two groups of common 

 pigeons given light dosage did the sugar return to a normal 

 value at the end of four hours as it clearly did in the ring doves; 

 nor was it at the apparent normal level after 22 hours, but our 

 failure to obtain the normal for these particular birds before 

 injection leaves the point uncertain. It is clear, however, that 

 in the group of 10 ring doves (Figure 1) which at the time of 

 sampling and during preceding weeks was being injected twice 

 daily (9:00 A. M. ; 7:00 P. M.) the blood sugar was again 



