238 



agriculture of maine. 



Table io. 

 La-ctation Record of Dorothy of Orono. 



After March 24, 1913, the cow never gave any milk. The 

 udder rapidly shrunk to a very small size and the animal began 

 to show the external characteristics of a bull. This change was 

 very slight at first but soon became much more marked. After 

 a lapse of 8 months the general extern<il appearance and the 

 behavior of the cozv were like those of a bull to a remarkable 

 degree. The neck had become thickened in its posterior parts, 

 and had developed a well marked crest, as is characteristic of 

 a bull. If the cow had been so screened that only her forequar- 

 ters and neck were visible any observer would have unques- 

 tionably pronounced her a male. The assumption of male char- 

 acters in these regions was complete and perfect. In the hind- 

 quarters the change from characteristic female conformation in 

 the male direction, while less striking than in the anterior parts, 

 was still clearly evident. The udder shrank away to a very 

 small size. The hips and rump took on the smooth rounded, 

 filled-out appearance which is characteristic of the bull but not 

 of the cow. 



The cow was slaughtered on February 18, 1914. Autopsy 

 showed as the only gross abnormality a simple cystic condition 

 of the ovaries. Under the microscope these cystic ovaries dif- 

 fered from the normal cow's ovary in but one essential respect, 

 namely, that they had no corpora lutea. 



A corpus luteum, or yellow body, is a peculiar cellular struc- 

 ture which forms in the ovaries of animals which give milk, 

 where an ovum has been discharged. This yellow body pours 

 into the blood a chemical substance, which is known to liave the 

 function (i) of preventing the ovary from discharging any 



