NUTKITIOtf OF DROSERA ROTinSTDIFOLIA. 19 



Munk (as quoted by Cramer) remarks that the catching and 

 driving away of insects may be of service to the plant ; but in the 

 digestion he can only see an injury. He suggests that the pecu- 

 liarity of the digestive process being both pathological and phy- 

 siological, seems to agree with the fact that in spite of a highly 

 differentiated organism, Dioncea appears to be approaching ex- 

 tinction. 



Cramer quotes (p. 34) Schenk, who, like Munk, finds it im- 

 possible to believe that a digestive process that kills the func- 

 tioning organ can be serviceable to its possessor. As Cramer 

 remarks, these pathological results are no doubt in some cases 

 the result of overfeeding. Schenk (quoted by Cramer, p. 34) 

 appears to doubt the digestive powers of Aldrovanda, because he 

 found it flourish for a long time in Knop's nutritive solution. 

 Cohn* remarks that Schenk' s results only prove that the leaves 

 of Aldrovanda can absorb nitrogenous (though not animalized) 

 fluids ; and he adds that his own experiments prove that these 

 plants do not flourish in pure water with no insects. 



Duval Jouvef observes that the fact of digestion causing the 

 death of Dioncea (Canby), and the results of Lawson Tait's ex- 

 periments (Nature, July 29, 1875), make him extremely doubtful 

 as to the process being any advantage to the plant. 



Casimir de Candolle % made a comparative experiment on four 

 Dioncea plants, two of which were fed and two starved. They were 

 carefully watched for six weeks, and no difference was noticed 

 between the two sets. M. de Candolle concludes that animal 

 food is not necessary to the plants. He is careful to point out that 

 the number of plants experimented on is too few to draw any^ 

 certain conclusions therefrom. 



Goppert § remarks that " the so-called carnivorous plants do 

 not absolutely require animal food for their support, and can 



well dispense with it." 



Ch. Cavallier addressed the question to a number of distin- 

 guished observers as to their opinion on the subject of vegetable 

 digestion. A few of the published replies are here given ||. 



* Thatigkeit der botan. Section der schles. Gesellsch. fur vaterl. Cultur, 1870, 



p. 113. 



t Causerie Botanique, Aug. 1876. 



t Archives des Sciences phys. et nat. Geneve, April 1876, p. 3. 



§ Thatigkeit der botan. Section der schles. Gesellsch. 1876, p. 101. 



An 



p. 56. 



c2 



