THE WHEAT CULTUEIST. 



33 



He also raised plants for the purpose in vases of sand 

 well pulverized and washed, so as to be able to free the 

 roots for examination, at a more advanced period with 

 the least possible injury. His numerous experiments 

 appear to have been conducted with the most scrupu- 

 lous care, for which, moreover, his well-known success 

 in analogous researches offers a sufficient guarantee. 



" It has long been known that roots absorb the nutri- 

 ment necessary for the plant, by means of the young 

 fibres which form the ultimate ramifications of the roots ; 

 that these fibres are terminated by a short portion of a 

 loose and soft textm-e called by botanists the spongiole. 

 Fig. 5 ; that this spongiole is the point of growth of the 

 fibre, usually bearing at its extremity a kind of cap of 

 a harder and drier texture, called the pileorhiza, «, Fig. 

 5, which is pushed forward by the fibre as it grows ; 

 and that, immediately below the spongiole, the fibre is 

 usually more or less invested with a short down consist- 

 ing of small spreading hairs. Gasparrini shows that 

 the spongiole itself seldom takes any part in the absorp- 

 tion of the nutriment for the plant, but is nothing more 

 than the young as yet imperfect part of the fibre, con- 

 sisting of cellular tissue in the course of formation ; that 

 the pileorhiza is a portion of the epidermis or covering 

 of the fibre, which, after a period of comparative rest, 

 is torn from the remainder of the epidermis and pushed 

 forward by the growth of the spongiole under it, and is 

 ultimately cast off, to be reproduced by similar causes 

 the following season ; and that in the great majority of 

 vascular plants the nutriment is either entirely or chiefly 

 absorbed by the root liairs formed on the young fibres 

 at tlie base of the spongiole, and which he on that ac- 

 count denominates suckers. 



2* 



