268 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The hypothesis that cleistogamic flowers are developed to preserve the 

 species when the others fail, is unsatisfactory, because these are produced 

 every year abundantly. 



The hypothesis that this development is due to lack of light is 

 probably partially true, but insufficient, as cleistogamic flowers are pro- 

 duced in abundance during sunny midsummer. 



The cleistogamic flowers develop seed more rapidly than do the 

 conspicuous ones. It is believed that the purpose of their existence is 

 the economical and speedy production of seed. — M. C. C. 



Digestive Processes. 



Proteolysis, Tryptophane in. By S. H. Vines, M.A., D.Sc, F.R.S., 

 P.L.S. (Ann. Bot. vol. xvi., No. 61, p. 1 ; March 1902).— The unity of all 

 life is strikingly shown in the similarity of the digestive processes in 

 plants and animals. In plants it is most generally associated with the 

 utilisation of reserve materials, but is occasionally met with in connection 

 with the absorption of food from without, when it is a process precisely 

 similar to the digestive processes of the higher animals, though somewhat 

 simpler in its details. Even in the first case above mentioned, of intra- 

 cellular digestion, the process agrees very closely with that of many of 

 the humbler animals. To this preface, given for the sake of those whose 

 physiology may not be quite recent, let us add that by proteolysis is meant 

 the digestive breaking up of proteids, and that tryptophane is a substance 

 formed in the breaking up of the proteid molecule into non-proteid sub- 

 stances and is characteristic of " tryptic " digestion. In a former number 

 of the annals the author gave evidence to prove that the proteolytic 

 enzyme of Nepenthes, as well as those of the Pineapple and of the 

 Papaw, are essentially tryptic in their mode of action. Here the author 

 writes : "I propose in the present paper to give a more complete account 

 of my observations on bromelin and papain, and to describe further experi- 

 ments which I have made with the enzymes of the Fig (Ficus Carica, L.), 

 of the Coconut (Cocos nucifcra, L.), of germinating seeds of the Bean 

 (Vicia Faba, L.), and of the Barley (Hordeum vulgare, L.), of Yeast 

 (Saccharomyccs Cerevisice, Meyn), and of the Bacteria of putrefaction, as 

 also with animal pepsin. I will so far anticipate as to say at once that 

 in all these cases, under appropriate conditions, I have succeeded in find- 

 ing tryptophane among the products of digestion of fibrin and Witte- 

 peptone." The experiments are described in considerable detail and many 

 points might be abstracted. In his conclusion the author writes : " The 

 additional instances that I have now given of the production of trypto- 

 phane, selected as they are from various classes and from different parts 

 of plants, bear out my previously expressed opinion that the proteolytic 

 enzymes of plants in general are essentially 1 tryptic' " An observation 

 made by the author bears strongly, in this case at any rate, against certain 

 views of the purpose of poison in plants, and his view to this effect must 

 be quoted : "I would add a few words regarding the observation that 

 hydrocyanic acid promotes proteolysis in certain cases. I regard this as 

 a matter of some importance, as it may, if followed up, throw light upon 

 the physiological significance of this acid in plants. Its general occurrence 



