OF INSECTIVOROUS PLANTS 435 



of enfeebled pitchers, which possessed a neutral or alkaline reaction; it 

 was recorded as much slower than the normal digestion, although its 

 products could be absorbed, in part at least, by the plant, provided the 

 putrefaction had not injured the pitcher. Goebel stated that the pitch- 

 ers of enfeebled plants frequently contain only water, and that such plants 

 may give results like those obtained by Dubois and by Tischutkin. 



The absorption of peptone by the pitchers was demonstrated. Six 

 pitchers of N. M aster siana were washed out; and a known volume of a 

 0.1 percent solution of peptone, containing 0.1 percent formic acid, was 

 placed in them. At the end of 66 hours, the pitchers were emptied. 

 Resorption and evaporation of the liquid had been but slight, it was clear, 

 colorless, free from bacteria, and contained only a trace of the mycelium 

 of mold. The formic acid content had not decreased; however, but a 

 faint trace of peptone remained, and an enzyme could not be detected. 

 Hence the peptone had been absorbed. These pitchers again secreted 

 liquor, and digested small pieces of meat. 



Clautriau (12) conducted experiments on plants of Nepenthes ynel- 

 amphora in their native habitat in Java. The liquor in non-stimulated 

 pitchers was neutral to litmus. When an unopened pitcher was merely 

 shaken, its liquor had a more or less acid reaction on the following day. 

 The reaction became acid after fine glass tubes, 1 to 2 cm. in length, were 

 dropped through the lid into the pitcher, or after 2 or 3 drops of tincture 

 of litmus were added to the liquor within the pitcher. Hence sUght 

 stimulation sufficed to cause the appearance of acid. The strongest 

 acid reaction in the stimulated pitchers was about equal to that possessed 

 by a solution, obtained by diluting 2 cc. of slightly fuming hydrochloric 

 acid with sufficient water to render the final volume 1 liter. The liquor 

 contained in solution a substance which was apparently thermolabile; 

 this substance caused insects to become wet and to sink. The liquor 

 did not contain a poison which kills insects. The insects were finally 

 digested, leaving only a residue of chitin; putrefaction did not occur. 

 The pitchers were sensitive to the presence of even exceedingly small 

 quantities of antiseptics, such as formaldehyde, chloroform, spirit of 

 camphor, essence of peppermint and of lemon, in the pitcher liquor; 

 these reagents caused a cessation of the secretion of acid and of digestion, 

 and the pitchers died in a few days. 



When coagulated egg-white was introduced into the pitchers, diges- 

 tion and absorption occurred. If but a small quantity of egg-white was 

 used, absorption equalled digestion; proteolytic products did not remain 

 in the pitcher, and a substrate for bacteria was lacking. If a large 



