Influence of Corpus lut^nnn Extracts upon Plain Muscle 13 



In other cases lonojitudinal strips of the small intestine were employed, six 

 experiments being made. Except in one case, which showed contraction — 

 althougii this did not appear until six minutes after immersion in the fluid 

 — the strip became relaxed, showincr diminution of tone, sometimes with, 

 and sometimes without, cessation of the "pendulum movements" (Hg. 12). 



Three experiments were made u])on the hjwer part of the colon of a 

 rabbit, which was excised, washed with Locke, tied at both ends, and 

 placed in the apparatus. In all oi these diminution of tone was observed, 

 usually with abolition of the "pendulum movements" (fig. 13). 



Fig. 14. — Longitudinal strip of portion of intestine ot cat: the intestine had been kept twenty- 

 four hours in an ice-chest. Notice the great diminution of tone with arrest of the rhythmic 

 movements as the result of immersion in 5 per cent, extract of fresh corpus luteum of cow 

 during the period marked by the strokes on the signal line. (Tliese strokes sliould be shifted 

 a little to the left. ) 



Intestine of Cat. — Eleven experiments were made on the intestine 

 of the cat, and one upon the jejunum of a young kitten. In the la.st 

 case diminution of tone was observed. In the adult cat the whole 

 intestine was not taken, but strips of the longitudinal muscular coat. Of 

 the ten experiments performed in this way, six exhibited diminution of 

 tone with cessation of "pendulum movements." These effects were 

 recovered from on substitutincr Locke solution. In two cases there was 

 increase of tone alonor with increase in the rate of the individual contrac- 

 tions. In the remainincr two cases no change could be observed. 



One experiment was made with a longitudinal strip of a piece of cat's 

 intestine which had been kept for twenty-four hours in the ice-chest. In 

 this case, great diminution of tone, with arrest of the " pendulum move- 

 ments," was produced (fig. 14). 



