THE WHEAT CULTUEIST. 



35 



might be suited for the nutriment of the plant ? It is 

 to the solution of this question that Gasparrini's experi 

 ments are chiefly directed, and he concludes that they 

 are entirely exuded from the suckers. 



" In the first place he adduces several experiments in 

 refutation of those who believe that the tender fibres of 

 roots possess some chemically dissolvent properties, and 

 that it is by such means that they are enabled to pene- 

 trate into masses of hard substances, whether inorganic 

 or organic, such as the woody tissue of living plants. 

 In the case of the common mistletoe growing on a pear 

 tree, he followed the radical fibres of the parasite from 

 the woody tissue through the alburnum and the par- 

 enchyma of the bark sometimes to the length of half 

 an inch. They could be clearly traced their whole 

 length, although forming an intimate cohesion with the 

 tissue of the matrix, except the spongiole at the extrem- 

 ity, which was always free ; but he never saw the slight- 

 est indication of any morbid alteration in the tissue 

 thus penetrated. 



"In the case of the young plants of wheat, rye, bar- 

 ley, rape-seed, and others which had been caused to 

 germinate under glass, the process of excretion was 

 readily observed. Previous to the formation of the ad- 

 hesive globules on the surface, the suckers were full of 

 a fluid in which floated a granular substance showing 

 clearly a circulation in two currents, the one ascending, 

 the other descending ; after a time the suckers opened 

 at the extremity and discharged the greater part of the 

 granular substance they contained, the discharge being 

 preceded by a peculiar motion analogous to that of 

 pollen grains before they burst. The contact of a drop 

 of warm water accelerated the discharge ; and if the 



