152 BACTERIA IN RELATION TO PLANT DISEASES. 



production of albumoses. The liquid in this case came from a repeatedly nourished pitcher and was 

 kept in the laboratory during the period of experiment (3 days). 



To determine whether digestion was in any way dependent on absorption he separated pitchers 

 from the plant at different intervals, after the addition of albumen, and in every case found that this 

 separation from the plant inhibited digestion. A comparative study was made of the tissues of adult 

 pitchers with and without nourishment by the addition of albumen. In adult pitchers which had 

 received additions of albumen, the tissues in the vicinity of the spiral vessels coming from the glands 

 and the tracheids which go to the vessels showed a manifest accumulation of proteids (De Wevre's 

 eosine test). 



Besides his researches in Java, Clautriau also worked on other species in hothouses in Europe, 

 especially N. maslersiana. 



For the separation of the products of digestion he used Neumeister's methods. His experiments 

 were as follows : 



He removed from a large pitcher the liquid containing the remains of insects, replacing it with 

 a mixture of 12.5 cc. of distilled water and 2.5 cc. of incoagulable albumen. In all his hothouse 

 experiments this albumen was used. The removed liquid (9 cc.) was filtered and divided into 3 parts. 

 To A, 20 drops of albumen were added, to B the same amount of albumen and a drop of dilute chlor- 

 hydric acid (0.01 cc. HO.). C was kept in a hot water bath at ioo for 6 minutes before receiving 

 the same treatment as B. A fragment of camphor was used in each case as an antiseptic. The tubes 

 were kept in the thermostat at 37 . After 3 days, A and B contained no albumen, no syntonin, and 

 only traces of albumoses; the peptonization was, therefore, complete. In C all the albumen had 

 disappeared; there was much syntonin, a little albumose, and no peptones. This result was con- 

 firmed by many experiments. At a low temperature (20 ) the same experiment gave different results. 

 After 5 days there was a little albumose present and doubtful traces of peptones, while a considerable 

 quantity of syntonin remained. Clautriau thinks, therefore, that temperature plays a large part in 

 the proteolysis. 



The experiments on absorption made in Java were repeated on hothouse plants with the same 

 results. In one case the liquid of a pitcher was replaced with distilled water and albumen, on three 

 different occasions. Each time the albumen was digested, and the products absorbed completely. 

 In thisway 32.5 cc. of the incoagulable albumen were digested without injury to the urn. Clautriau 

 thinks that as the peptones are diffusible it is natural that they should be the first substances absorbed. 

 In only two cases did he succeed in demonstrating peptones in the pitcher: Once in a pitcher of feeble 

 vitality, once after adding methylene blue which seemed to retard absorption. 



To prove that the plant really derives benefit from pitcher digestion, Clautriau undertook to 

 show that the nitrogen of albuminoid substances was really absorbed by the plant and not present 

 in the pitcher liquid in another form. The method used was to determine the quantity of nitrogen 

 present in the pitcher, after a certain period of digestion with a known quantity of albumen. Accord- 

 ing to Kjeldahl's method, 10 cc. of incoagulable albumen gave a quantity of ammonia equivalent to 

 14 cc.of decinormal sulphuric acid. The same amount of albumen, after 7 days digestion in a pitcher, 

 when subjected to the same treatment neutralized only 2.8 cc. of the decinormal sulphuric acid. 

 In a second experiment it neutralized 2.7 cc. Thus after a week only 20 per cent of the nitrogen 

 remained, part of which may have come from zymase and from the chitinous remains of insects. 



Clautriau states also that the glands are the agents of absorption as well as of secretion. Micro- 

 chemical examination showed that after digestion and absorption had taken place, the glands, and 

 cells surrounding them, showed marked accumulation of albuminoid substances, while no such con- 

 dition was found in the epidermal cells. Clautriau further states that he isolated a small quantity 

 of true peptone. He failed to find either leucin, tyrosin, or amido-acids, and hence considers the 

 enzym a pepsin. Starch is not digested. 



In 1901, Vines published another paper on the proteolytic enzyme of Nepenthes, first 

 reviewing Clautriau's researches to which in some instances he takes exception, though 

 on the whole he regards them as important. 



In the first place Vines states that, contrary to Clautriau's inference, the addition of a little 

 hydrochloric acid or of an organic acid hastens the process of digestion, although naturally acid pitcher 

 liquid will digest proteid. Neutral pitcher liquid will not digest it at all. Moreover, with regard 

 to the doubt expressed by Clautriau as to the presence of an enzym in the liquid of unopened 

 pitchers, he states that the liquid is very active when properly acidified. 



The most important point of difference, however, is the nature of the enzym, which Clautriau 

 claims is a pepsin, on the ground that he has been unable to detect leucin or tyrosin: Vines on the 

 other hand considers it a trypsin. 



