106 DROSERA EOTUNDIPOLIA. [Chap. VL 



case of Pinguicula. If so, Drosera will profit to a slight degree 

 by absorbing mutter from such seeds. 



Summary and Concluding Remarks on the Digestive Power 

 of Drosera. 



When the glands on the disc are excited either by the 

 absorption of nitrogenous matter or by mechanical irritation, 

 their secretion increases in quantity and becomes acid. 

 They likewise transmit some influence to the glands of the 

 exterior tentacles, causing them to secrete more copiously; 

 and their secretion likewise becomes acid. With animals, 

 according to SchiflF,** mechanical irritation excites the glands 

 of the stomach to secrete an acid, but not pepsin. Now, I 

 have every reason to believe (though the fact is not fully es- 

 tablished), that although the glands of Drosera are continu- 

 ally secreting viscid fluid to replace that lost by evaporation, 

 yet they do not secrete the ferment proper for digestion when 

 mechanically irritated, but only after absorbing certain mat- 

 ter, probably of a nitrogenous nature. I infer that this is 

 the case, as the secretion from a large number of leaves 

 which had been irritated by particles of glass placed on their 

 discs did not digest albumen; and more especially from the 

 analogy of Dionsea and Nepenthes. In like manner, the 

 glands of the stomach of animals secrete pepsin, as Schiff 

 asserts, only after they have absorbed certain soluble sub- 

 stances, which he designates as peptogenes. There is, there- 

 fore, a remarkable parallelism between the glands of Drosera 

 and those of the stomach in the secretion of their proper acid 

 and ferment." 



** ' Phys. de la Digestion/ any special action of the so-called 



18C7, torn. II. pp. 188. 245. peptoRPHs. He wrItPH. " I find 



[It will be seen from the that ac-ld and popain make tholr 



facts given In a footnote at p. appenrnnce nImoHt IniiiKMllatclr 



81, that even If we accept after the Introduction of a stiirrh 



Scblff's peptoeen theory, the evi- solution Into the Ktoniiwh. The 



dence on the botanical side In unnjc thln>r nnturnllv followH on 



against the existence of the the Introduction of SchltT's jjcpto- 



ai>ove suggeHted pnrnllelltni. gens, ho that no ln<-onsli|i>riib1e 



Moreover, RchlffB peptogcn the- (|unntlty of acid and pepsin Is In 



ory Is not generally accciifcd by readiness for a subseiiuent act of 



physiologists. Professor Sander- dicesllon, whirh Is. In conse- 



son has called my attention to qiience, rendered far more ener- 



Ewnld's views on this i|uestlon getlc." 



ns given In his ' Kllnik der V'er- lialilenhaiu. In Hermann's 



dannngs krankhelten. (I) Die ITandbuch der I'hvslolojjle.' vol. 



Lcbre von der VenlauunK.' 18sn. v. part I. p. 1.5.% also criticises 



p. OL Ewald does not believe In Schiff's theory, and shows that 



