The Corpus Luteum of the Guinea Pig 



71 



sections cut at 7 (x; every 5th section was mounted and 

 stained in haematoxylin and eosin. 



Measurements of the corpora lutea and the mature follicles 

 were made across three diameters. One of these was got by 

 counting the number of sections in which the organ appeared 

 and the other two by measuring with a micrometer eyepiece 

 the largest section of the organ ; measurements were made at 

 right angles through the centre of the section. The product 

 of the three diameters in mm. 3 (D 3 ) has been used throughout 

 to express the dimension of these organs from which true 

 volume may easily be calculated. 



The Corpus Luteum 

 Quantitative observations 



At ovulation, which occurs about fifteen hours after parturi- 

 tion, the mature follicle measures about 1 mm. in diameter, by 

 which time changes suggestive of luteinization have already 

 commenced in the membrana granulosa. Fig. 1 gives the mean 



8 4 

 1 



"« 



• • 





O 5 IO 15 20 



No. of days after oestrus 

 Fig. 1. Mean D 3 in mm. 3 of the corpora lutea of the guinea pig (£) and 

 after sterile mating (0). 



