Francis E. Lloyd —12— Carnivorous Plants 



occurred after some days during which bacteria had accumulated. 

 Dubois (1890) found the sterile fluid from unopened pitchers without 

 action, but that from recently opened pitchers, while still clear, acted 

 vigorously on egg-albumin. Dubois voted for the bacterial action 

 theory. Couvreur (1900) argued that Vines' results were due to the 

 interaction of the reagents on one another. This totally negative 

 attitude had been combatted by Goebel (1893). In a prehminary ex- 

 periment, he took a pitcher of A^. paradisiaca (a hybrid) which contains 

 a "clear, odorless and tasteless fluid" and in it placed a bit of flbrin, 

 with one in water as control. In six days the fibrin was broken up 

 and bacteria were plentiful, and the fluid showed a neutral or sHghtly 

 alkaline reaction. A yellow reaction was obtained in the water but not 

 in the pitcher, by which the products had been resorbed. No peptone 

 had been produced. Cultures showed the presence of Bacterium 

 fiiiorescens liquejaciens. This result admittedly agreed with those of 

 Dubois and Tischutkin. But Goebel pointed out that the plant was 

 not normal. When he took a strong, wefl grown plant he found other- 

 wise. It had three pitchers, an old one, a strong vigorous one and an 

 unopened one. In the old one, a wasp was attacked and digested. In 

 three days the fluid was alkaline and bacteria and infusoria were plenti- 

 ful. In the open but vigorous pitcher a fly had been caught. A bit of 

 fibrin was introduced and was attacked in one hour. In 3 hours pep- 

 tone was demonstrable. Another bit of fibrin together with 0.2% HCl 

 were introduced, and this was digested in 40 minutes, and no bacteria 

 could be found. The fluid of the unopened pitcher was neutral. In 

 its fluid fibrin accompanied by 1% formic acid was digested in 12 

 hours, and no bacteria were detected after 8 days. He concluded 

 therefore that a peptone forming ferment was present in the fully 

 normal pitchers. He further showed that normal pitchers, when stim- 

 ulated by the presence of an insect, secrete formic acid. By way of 

 further control he tried to see if fibrin might be digested by the secre- 

 tions of the lid, with negative results. To do this he fastened a bit of 

 fibrin on the under side of the lid with moist filter paper. Thus 

 Goebel confirmed Vines' conclusions. In general support of the view 

 that the bacteria of decay have nothing to do with the digestion of 

 insects in normal plants in their native habitats Goebel quoted 

 Wallace who wrote in The Malay Archipelago as foflows: "We had 

 been told that we should find water at Padangbatu, but we looked for 

 it in vain, as we were exceedingly thirsty. At last we turned to the 

 pitcher plants, but the water contained in the pitchers (about half a 

 pint in each) was full of insects and otherwise uninviting. On tasting 

 it, however, we found it very palatable, though rather warm, and we 

 all quenched our thirst from these natural jugs." And stiU earlier 

 Hermann Nicolaus Grimm recorded (in 1682) the discovery of "aqua 

 dulcis, limpida, amabihs, confortans et frigida" in the pitchers, and the 

 fluid from six to eight of them was sufficient to satisfy a thirsty person. 

 That our greenhouse cultivated plants, because of their compara- 

 tively feeble vitality as compared with plants in their native habitats, 

 may often behave abnormally, is indicated by the observation of 

 MoHNiKE, whom Goebel cites, who said that the pitcher almost al- 

 ways contains a mass of dead insects including even large beetles. 



