PEPTOmSING FERMENTS. 345 



■vegetable kingdom by the remarkable phenomena observed in the so-called insec- 

 tivorous plants, of which I shall speak more in detail shortly. My earlier studies 

 on the germination of various seeds left no doubt that seedlings dissolve and make 

 active their proteinaceous reserve-materials by means of peptonising ferments. Gorup- 

 \ Besanez was, however, the first to detect peptonising ferments in seeds. This he 

 , did in the seeds of the Vetch, Hemp, Flax, and Barley ; and Krukenberg found an 

 energetic peptonising ferment soon afterwards in the protoplasm of a Myxomycete, 

 inamely, in the yellow plasmodium of the 'flowers of tan' (^^tkalium. septicum). More 

 recently, a very energetic peptonising ferment in the latex of Carica Papaya has 

 attracted particular attention, and a similar ferment has been detected in the latex 

 of the common Fig (Ficus Caricdf. As we come to know the proteinaceous reserve- 

 materials of plants better, and if we follow their behaviour in the animal body also, 

 it can scarcely be doubtful that, in spite of incomplete knowledge, the assumption 

 is nevertheless warranted that peptonising ferments are perhaps universally dis- 

 tributed in plants ; moreover, peptones, the result of their activity, have actually been 

 detected by Schulze in the seedlings of the Lupine. The peptonising ferments in 

 the animal body, where they occur particularly in the mucous membrane of the 

 stomach, are much better and more generally known than in plants. Exceedingly 

 small quantities of them are able to lignify and dissolve coagulated egg-albumen, 

 blood-fibrin, or muscle, in the presence of an acid, especially hydrochloric acid, with 

 great energy, and so convert them into a condition in which the proteid matters, 

 while retaining their essential chemical properties, will diffuse through closed tissue 

 cells, to be reconstructed into organised proteid substances at suitable spots in the 

 organism, and to serve for the construction of tissues. 



In the peptonising of proteid substances, as in the action of diastatic ferments, 

 it is a matter of a relatively slight chemical change. A much more profound 

 decomposition of the proteid bodies takes place, on the contrary, when they are con- 

 verted into Asparagin '^ and other split products. Among the latter, in any case, a 

 sulphur compound, probably sulphuric acid, must occur. But, besides asparagin, 

 Tyrosin, which arises in the artificial splitting of proteid bodies, has also been 

 observed by Borodin in many cases. It is not yet known whether or how far any 

 ferment action occurs in this case. In any case, however, the formation of asparagin 

 has a similar significance for the transport of nitrogenous substance that the formation 

 of sugar from starch-grains has ; since- by means of the conversion of proteid bodies 

 (which are only slowly and with diflBculty diffusible even in the dissolved, state) into 

 asparagin, which is a crystallisable substance forming solutions which readily diffuse, a 

 means is obtained for transporting the nitrogenous substance in the closed parenchyma 

 to the places where it is made use of. Consequently asparagin is formed on the 

 germination of seeds, tubers, root-stocks, and when the winter-buds of woody plants 

 put forth their shoots ; this penetrates from the reservoirs of reserve-materials into 

 the young growing parts, and is there employed for the formation of protoplasm. 



' On the ferment in the latex of Ficus Carica cf. Hansen, ' Sitzungsber. der physical, med. Soc. 

 zu Eriangen' (Nov. 8, 1880). 



' The literature on Asparagin is cited in Pfeffer's ' Pflanzen-physiologie' (§ 59). Borodin's 

 treatise, the one chiefly made use of in the text, is in Bot. Zeitg. 1878 (Nos. 51, 52). 



