444 Mr. J. Walton on the Genus Apion. 



as the blood presents a visible organization, the nutrient fluid of 

 plants must also. And why ? asks Prof. Mohl : there is no rea- 

 son which should force such a conclusion on us ; on the contrary, 

 the presence of granules could scarcely have any relation to the 

 nutrient power of the vegetable juice. The anatomical conditions 

 of the plant would present every difficulty to their movement ; 

 and if, wth M. Schultz, we perforate the walls of cells to give 

 passage to vessels which no one has seen, we may establish what- 

 ever physiological laws we please, and any kind of deductions 

 from them. 



The elatine is not the true organic constituent of the latex 

 which represents vegetable iibrine. This comparison has been 

 shown above to be founded on errors of observation ; but it will 

 be seen to be still more contrary to natm'e, if we consider the 

 chemical relations of fibrine and caoutchouc. While animal 

 bodies are almost entirely composed of fibrine, or chemical com- 

 binations nearly identical with it, the great mass of the substance 

 of vegetables is formed of matters which equally present the 

 greatest chemical affinity to each other, which frequently pass 

 from one into the other, and may be artificially transformed ; and 

 all these differ extremely from caoutchouc, since the latter con- 

 tains no oxygen. How is it possible, asks the author, to consider 

 the almost insoluble caoutchouc as the principal agent in the 

 nutrition of plants ? It is contrary to all the most recent obser- 

 vations in vegetable physiology. The latex is found in the 

 smallest proportion in the youngest parts, where formation and 

 nutrition are most active, and where it would be most necessary ; 

 while caoutchouc, from its chemical composition, cannot be in- 

 cluded in the series of neutral combinations through which we 

 have a right to admit a du-ect passage from sugar to ligneous 

 fibre. M. Schidtz is also unable satisfactorily to explain the fact 

 that the milky juices are mostly poisonous. 



Prof. Mohl concludes by stating that he is absolutely ignorant 

 of the physiological value of the latex. We have no positive 

 facts on which to base any certain theory ; but one thing, he 

 says, is settled, which is, that the theory of M. Schultz must be 

 regarded as an entirely unsuccessful attempt to resolve the 

 enigma, and that the term vital juice must be rejected. 



L. — Notes on the Synonymy of the Genus Apion, with Descriptions 

 of Five new Species, ^c. By John Walton, Esq. 



Some time back I made an attempt to correct the synonymy and 



to determine the species of the interesting little British Curcu- 



lionites arranged under the generic title Apion *. I have since 



* See Ent. Mag. vol. v. p. 8. and p. 254. 



