Iletin and Reproduction 



247 



is of interest in connection with studies elsewhere now being 

 made upon insulin, since it seems probable that some effects of 

 the hormone scarcely observable in mammals may be success- 

 fully studied in the pigeon. Table 2 records our chief observa- 

 tions on this point except for data concerning symptoms and 

 extent of the hypoglycemia induced by heavy dosage. 



Certainly some of the symptoms observed in rabbits 2 are 

 sometimes duplicated in the impaired vision and incoordinate 

 movements of the heavily dosed pigeon. These movements 

 strongly resemble those of the ataxic pigeon. Convulsions were 

 observed only in three of the four birds killed by the extract. 

 Unlike the rabbit the bird becomes quiet, apparently very tame 

 (really impaired vision?), and gives little or no evidence of 

 hunger for many hours or days. Though the intestines of 

 most of our heavily dosed birds were made free of food before 

 injection, and though none were permitted to take food earlier 

 than 48 hours after dosage, some birds had to be forcibly fed 

 (impaired vision?) even at the end of 72 or 96 hours. No 

 abscesses have resulted from more than 700 injections. 



Two lots or shipments of the extract have been used. The 

 data of table 2 were obtained almost equally from the use of 

 the two preparations. The data of Table 1 are all from the 

 first lot kept in a refrigerator and used when aged one to two 

 months. Its capacity to lower the blood sugar at the end of 

 two months, in one-sixth unit doses, was somewhat less than 

 that of the second lot as tested against the latter within 48 

 hours after its arrival at the laboratory; the values obtained 

 being .082 per cent, sugar for lot 1, and .062 per cent, sugar 

 for lot 2. These data were obtained as part of the studies 

 reported in the accompanying communication. 6 Other data 

 obtained in connection with that study indicate that though the 

 normal blood sugar of all the kinds of pigeons used is notably 

 higher than that of the rabbit, the value in the pigeon was 

 sometimes reduced to .020 to .040 per cent, without convul- 

 sions or death. Bird No. 16 which died after 8.5 hours, gave 

 single unchecked values of .020 per cent, two hours after dosage 

 and .010 per cent, after four hours. Another of the birds which 

 died 28-34 hours after injection gave a value of .025 per cent, 

 after twenty-one hours. Two birds survived though they gave 

 sugar values of .020 and of .030 and .040 per cent. 



6 Honeywell and Eiddle, Proc. Soc. Exp. Biol, and Med., 1923, xx, No. 5. 



