
eggs in the uterus, premature oviposition of from 2 to 18 hours 
in approximately 50 per cent of the birds was induced. These 
eggs were either soft-shelled or had measurably reduced shell 
content. Eggs from birds injected repeatedly with acetylcholine, 
showed decreased volume and increased viscosity of the thin: 
white. 
Ephedrine sulfate on the other hand delayed oviposition 
up to 24 hours when injected intramuscularly at the time the 
egg was in the uterus. Weiss and Sturkie (1952) confirmed their 
previous work on the effect of acetylcholine and ephedrine on 
influencing premature oviposition and delayed oviposition, re- 
spectively. The dose administered to 2-year old White Leghorn 
chickens were between 50 and 100 mg. of acetylcholine and 25 mg. 
or larger amounts of Ephedrine. These workers observed that 
histamine will also produce premature oviposition with a total 
dose of 15 mg. The amount of shell found on the eggs varied de- 
pending on the time the eggs had spent in the uterus before the 
drug was injected. 
Sykes (1955) delayed oviposition in Brown Leghorn 
chickens by administration of 1.0 mg. or more adrenaline, The 
author suggested that the most likely site of action of the drug 
would be the uterine muscle. Oviposition took place after in- 
jecting the birds with pituitrin. The doses that were too small 
to delay oviposition were nevertheless effective in lowering 
production. Inhibition of ovulation and follicular atresia 
have been caused by fright, which in mammals is known to promote 
the release of adrenaline -- and the same may be true of the 
fowl. Adrenaline may act directly on the follicles or through 
the pituitary gland. 
6. Shell structure as affecting fertility or hatchability. 
Pritsker (1941) reported that up to 50 per cent of 
duck eggs occur with a glossy "fatty" surface. Chemical analysis 
of shells of fatty and non-fatty eggs showed large differences 
in composition. In shells with fatty deposits, the protein had 
been supplanted by fats to the extent of 70 per cent, fats con- 
tributing over 80 per cent of the total quantity of organic 
matter. In studies carried out to find the effect on hatch- 
ability, it was found that the per cent of dead germs up to 7 
days was 15 per cent in the fatty eggs as compared to 5 per cent 
in non-fatty eggs; between 7 and 21 days, it was 28 and 10 per 
cent, respectively. The per cent fertile eggs that hatched was 
23 per cent for fatty eggs as compared to 52 per cent for non- 
fatty eggs. The per cent of strong ducklings was greatly re- 
duced also. Pritsker believed that the presence of the "fatty" 
deposits on the shells of ducks is not the cause of the high 
death rate of embryos, but a sign of more vital changes within 
the eggs themselves. 
29 
