Dioncea Muscifiila, Ellis. 37 



The secretion had all the chemical, physical, and optical 

 characteristics of that poured out round a nitrogenous body. 

 It at once gave a decided acid coloration to litmus test paper, 

 had a thick mucous consistence, so that it could be drawn out 

 into threads, and when a little was placed on a slide aiv' 

 treated with alcohol it coagulated and assumed under the 

 microscope a delicate myxoid or amoeboid granular areolation. 



But to prevent the possibility of tissue rupture during suc- 

 cessive irritations, a piece of glass dipping-rod was heated and 

 shaped so that a smooth spindle-like thickening was left in 

 the middle of two thin elongated handles. The swollen bulb 

 of the rod was then placed on a clean dry leaf, the handles 

 projecting from the lower and upper ends of the closed blade. 

 After successive intervals of two hours the rod was re- 

 peatedly raised and lowered so as to irritate the hairs. When 

 the leaf-halves were pulled slightly asunder after sixteen 

 hours, copious secretion was going on. In this as in the 

 above and succeeding experiments the leaves remained closed 

 from eleven to fifteen days, and during the greater part of 

 that time were bathed with the secretion. Strands of clean 

 cotton thread have been inserted, and pulled back and for- 

 ward at intervals of one to two hours for eleven to thirteen 

 hours. The leaves secreted freely after fourteen to twenty 

 hours. One that was similarly treated, but stimulated at 

 intervals of two to four hours, began to secrete after thirty- 

 one hours, but only poured forth copiously after three days. 

 The secretion steadily increased till at least the fifth clay. It 

 is a mistake, therefore, to suppose that the secretion ceases 

 after one or even two days activity. This has been verified 

 by numerous other experiments. 



With such results before us it seemed highly probable that 

 continued electrical stimulus would also excite secretion. 

 The terminals of a battery were slightly bent so as to accom- 

 modate themselves to the external, slightly convex, basal 

 surfaces of a leaf after being shut. On application of the 

 terminals to the external surface the halves closed by electrical 

 stimulus and gradually tightened up. Three experiments were 

 thus made and proved entirely successful. The secretion 



