6 



Itagaki 



luteum upon the excised organ could be determined even after the uterus 

 had been kept as long as three days in the ice-chest, although under these 

 circumstances the result is less marked (fig. 4). 



Fir, 3. — Quiescent uterus of rat stimulated to activity by immersion in extract of 



corpus luteum. 



Fig. 4. — Tracing from the cornu of a rat's uterus which had been kept in an ice-chest for three 

 days. Between the two marks extract of corpus luteum was acting upon the uterus. Notice 

 its stimulant action. (The signals should be shifted a little to the left. ) 



In rare cases the effect of Ringer extract of corpus luteum, whether 

 fresh or dried, produced, instead of increase of tone and increased rapidity 

 of the rhythmic contractions, the opposite effect, viz. diminution of tone, 

 which might amount to complete loss of tone, and diminution in height, or 



