Inrtueuce of Corpus luteuiu Hxtracta upon Plain Muscle 



19 



upon the uterus of dirterent animals with the- employment of the 

 same extract : — 



Table X.— Corpus ldtbdm Extract I. 



Table XI. — Corpus luteom Extract II. 



Table XII. — Corpus luteum Extract III. 



Further, when the same uterus is used, different extracts may give contrary 

 results. This is shown in Table XIII. : — 



Table XIII. 



It is clear, then, that the ditterences of response of the uterus to corpus 

 luteum extract are not due to differences in the condition of the uterus 

 but to differences in the samples of extract used for investigation. 



In order to determine whether these differences were due to the 

 condition of development of the corpora lutea which were used for obtain- 

 ing the extract, I made extracts from corpora lutea of different ages, 

 i.e. of different degrees of development. I thought it not improbable that, 

 since most of the corpora lutea which we employed were selected on account 

 of their being in an advanced condition of development, it might be possible 

 to obtain a different result from extracts made from other corpora lutea 

 which were less developed. With a view to test this notion, I made a 

 series of experiments with extracts from corpora lutea showing different 



