12 



BULLETIISr 51, IT. S. DEPARTMENT OF AGRICULTURE. 



EGGS HAVING SETTLED YOLKS. 



Table 5 shows another type of deterioration, which is further ad- 

 vanced and more specific than that meant by the general term 

 " stale."" The yolk has become more opaque and consequently clearer 

 in outline when viewed by the aid of the candle and has fallen to the 

 pointed end of the shell (see PI. Ill), where it turns sluggishly when 

 rotated. Very frequently when these eggs are opened the yolk is 

 seen to have a very thin, weak membrane. During warm weather, 

 when incubation goes on almost continuously, though very slowly, 

 these eggs with settled yolks frequently show a germinal area about 

 one-fourth inch in diameter, having a visible white line through 

 their center — the "primitive streak" of the embryologists. (See 

 PI. II.) Their odor is generally good and their taste not objection- 

 able, except for soft boiling or poaching. 



Table 5. — Individual eggs with settled yolks. 





Date of 

 exami- 

 nation. 



White. 



Yolk. 



Whole 



egg. 



Number of 

 gas-producing 

 bacteria per 



gram in 

 lactose bile. 





Sample 

 No. 



Total number of bacteria per gram on 

 plain agar. 



Description. 





Ineu- 



bated 



at20°C. 



Incu- 

 bated 

 at37_°C. 



Incu- 

 bated 

 at20°C. 



Incu- 

 bated 

 at37°C. 



Incu- 

 bated 

 at37°C. 



White. 



Yolk. 





4004 



1911. 

 June 12 

 June 13 



...do 



...do 



...do 



...do 



1912. 

 Aug. 31 

 ...do 



70 

 





 30 

 20 









 





 

 















 





 

 







6' 





 

 







Watery white. 

 Enlarged hatch spot; 

 bloate^l yolk. 



Enlarged hatch spot. 

 Enlarged hatch spot; 

 bloated yolk. 



Marked shrinkage. 



4013 



4014 

 4015 

 4016 



4018 

 41089-7 



30 



20 

 20 

 40 



30 









 10 

 



10 







64,000 

 lOatlOO 



54,000 

 240, 000 

 at 100 



at 100 

 at 100 



Oat 100 

 at 100 

 at 100 

 at 100 



Oat 100 

 Oat 100 

 at 100 



Oat 100 

 at 100 

 at 100 

 Oat 100 

 at 100 

 Oatl(X) 

 at 100 

 Oat 100 

 Oat 100 



Oat 100 

 at 100 



41089-8 















Very weak yolk which 



41089-12 



...do 

















broke when egg waa 

 opened. 



41089-18 



...do 















Marked shrinkage. 



41089-19 



...do 















Marked shrinkage; yolk 



41089-21 



...do 















broke when egg was 

 opened. 

 Marked shrinkage. 



41089-27 



...do 















Decidedly weak yolk 



41089-28 



...do 















which broke when 

 egg was opened. 

 Marked shrinkage. 



41089-33 



...do 















Do. 



41089-38 



.. do.... 















Do. 



41089-39 



...do 

















Marked shnnkage; yolk 



41089-41 



...do 















broke when egg was 

 opened. 

 Marked shrinkage. 



41089-42 



...do 















Do. 



41089-44 



...do... . 















Marked shnnkage; yolk 



41089-45 



...do 















broke when egg was 

 opened. 

 Do. 



41089-46 



...do 















Do. 



41089-50 



...do 















Marked shrinkage. 



41089-53 



.do 















Do. 



41089-55 



...do 















Do. 



41089-57 



...do 















Do. 



41089-58 



...do 















Do. 



41089-59 



...do 















Do. 



41089-61 



...do 













Yolk broke when egg 



41089-62 



...do.... 













-was opened. 

 Marked shrinkage. 



41089-63 



...do 





1 















i 











1 at the dilution given indicates that no organisms were ob-servcd on the plate. 



