THE EXPERIMENTAL PRODUCTION OF HYPO- 

 TYPICAL OVARIES THROUGH UNDERFEED- 

 ING. A CONTRIBUTION TO THE ANALYSIS 

 OF STERILITY. 1 



LEO LOEB. 



In former communications we described a condition of the 

 ovaries in which the follicles become atretic, usually before they 

 have reached medium size. Mature follicles are not produced 

 under these conditions and sterility ensues which persists as 

 long as this condition lasts. 1 Such ovaries we designated as 

 hypotypical. We observed those changes especially in guinea 

 pigs in which the corpora lutea had been burnt at a certain 

 period after ovulation. We must assume that the burning of 

 a part of the ovary caused a "tissue shock" in the remaining 

 part of the ovary which, without killing the follicles, weakened 

 the granulosa cells and thus prevented their further development 

 and caused their early disintegration. In addition we found this 

 change in a number of other animals, some of which had not yet 

 been in heat, and had consistently refused copulation, although 

 their age was such that we might have expected to find them 

 sexually active. In some other cases in which as the microscopic 

 examination showed, ovulation had failed to take place after 

 the conclusion of the last sexual period notwithstanding the 

 degeneration of the corpora lutea, hypotypical ovaries were 

 likewise found. This suggests that this condition may be the 

 cause of long-lasting or perhaps perpetual sterility. This hypo- 

 typical condition of the ovaries is of theoretical interest, inas- 

 much as it represents a state of low developmental energy of an 

 organ that is normally in a condition of constant change. From 

 a practical point of view it is of importance because it can lead 

 to sterility of the gqnads. It seemed to us therefore of interest 



1 From the Department of Comparative Pathology, Washington University 

 Medical School, St. Louis. 



2 Leo Loeb, Zentralblalt f. Physiologie, 1911, XXV., No. 9; Virchow's Archiv, 

 1911, CCVL, 278. 



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