378 



Scientific Proceedings (124). 



been studied, but only figures obtained for adult reproducing 

 females are here considered. 



All samples were obtained by needle-puncture of the heart. 

 Unfortunately, this procedure proved capable of producing occa- 

 sional ovulations into the body cavity and also the resorption in 

 the ovary of the nearly ripe ova. Since duplicate samples had to 

 be taken from at least two different stages of ovulation it was 

 possible to kill the bird only after the final sample was obtained. 

 This circumstance and the disturbing effects of the puncture 

 noted above unite to make it impossible to know in a few special 

 cases at which stage with reference to ovulation the sample was 

 taken. Such cases are indicated in the table. Nearly all figures 

 of the table represent duplicate determinations made at intervals 

 of one day to three weeks, and — in most cases — these determina- 

 tions checked to within 10 mgms. Data were also obtained for 

 suprarenal size at the time each bird was killed, but since only 8 

 of the 20 females used were entirely free from Ascaridia (none ob- 

 viously tubercular) these data throw little further light on the 

 relation of suprarenal size to ovulation; for, in the work referred 

 to above 1 it was shown that the suprarenals of birds thus infested 

 are usually continuously enlarged, are probably diseased, and do 

 not show any definite hypertrophy at ovulation. 



From 14 of the 20 females comparisons were obtained of the 

 mid-ovulation stage with a stage more or less removed from ovu- 

 lation. Of these 14 tests 12 show unquestionably higher values 

 for the mid-ovulation stage than for stages more remote from the 

 ovulation period. Moreover, both of the two exceptions proceed 

 from samples taken at periods so far removed from both the previ- 

 ous and succeeding ovulations (see table) as to make it possible 

 that instead of being really remote they may each represent a 

 stage immediately preceding an ovulation which was suppressed 

 by the heart punctures by which these samples were obtained. 

 Again, in one of these two cases the comparison made is not with a 

 mid-ovulation stage, but with stages 36 and 12 (?) hours pre- 

 ceding ovulation. For the remaining 6 of the 20 birds determina- 

 tions are available from only one stage — these birds failing to 

 survive the heart-punctures. In each of these six cases the 



'Loc. cit. 



