Chap. XV.] ON THE DROSERACEL^. 293 



surprising that they should readily allow fluids to pass in- 

 wards; aud this inward passage would deserve to be called 

 an act of absorption, if the fluids combined with the con- 

 tents of the glands. Judging from the evidence above given, 

 the secreting glands of many other plants can absorb salts 

 of anunouia, of which they must receive small quantities from 

 the rain. This is the case with two species of Saxifraga, 

 and the glands of one of them apparently absorb matter from 

 captured insects, and certainly from an infusion of raw 

 meat. There is, therefore, nothing anomalous in the Drose- 

 raceae having acquired the power of absorption in a much 

 more highly developed d^ree. 



It is a far more remarkable problem how the members of 

 this family, and Pinguicula, and, as Dr. Hooker has recently 

 shown. Nepenthes, could all have acquired the power of 

 secreting a fluid which dissolves or digests animal matter. 

 The six genera of the Droseracese have probably inherited 

 this power from a common progenitor, but this cannot apply 

 to Pinguicula or Nepenthes, for these plants are not at all 

 closely related to the Droseraceae. But the difllculty is not 

 nearly so great as it at first appears. Firstly, the juices of 

 many plants contain an acid, and, apparently, any acid 

 serves for digestion. Secondly, as Dr. Hooker has remarked 

 in relation to the present subject in his address at Belfast 

 (1874), and as Sachs repeatedly insists," the embryos of 

 some plants secrete a fluid which dissolves albuminous sub- 

 stances out of the endosperm; although the endosperm is 

 not actually united with, only in contact with, the embryo. 

 All plants, moreover, have the power of dissolving albumi- 

 nous or proteid substances, such as protoplasm, chlorophyll, 

 gluten, aleurone, and of carrying them from one part to 

 other parts of their tissues. This must be effected by a 

 solvent, probably consisting of a ferment together with an 

 acid." Now, in the case of plants which are able to absorb 

 already soluble matter from captured insects, though not 



" ' Traits do Botnnlquo.' Srd tho aid of Dr. H. Will, has aotu- 



wllt. 1S74, p. S44. See also for ally made the discovery that the 



following facts pp. 64, 70, 81i8, stn-ds of the vetch contain a fer- 



831. nient, which, when extracted hy 



" Since this sentence was glycerine, dissolves albuminous 



written, I have received a paper substances, such as fibrin, and 



by Gorup-Besanez (' Berlchte der converts them Into true peptones. 



Deutscheri Chem. (Jesellschaft.' [See, however, Vines' ' Plivslology 



Berlin, 1S74, p. 1478), who, with of Plants,' p. 190.-F. D.] 



