so VEGETABLE ORGANOGRAPHY. 



CHAPTER VII. 



OF THE SPONGIOLES AND SUCKERS. 



I HAVE designated under the name of Spongy Pores 

 (pores spongieux ) , or Spongioles (spongiolce), certain 

 external parts of the tissue, which have a most energetic 

 tendency to absorb the fluids with which they are in 

 contact; and they seem, in this case, to act as very 

 hygroscopic little sponges. They appear formed of a 

 very close cellular tissue, composed of round cellules. At 

 first, I only referred to this class of organs those which 

 are observed at the extremity of the roots ; but I believe 

 that several kinds of Spongioles must now be distin- 

 guished. 



1st. The Radical Spongioles, (spongiolce radlcales; 

 sponqioles radicales,)'a.ve situated at all the fibrous ex- 

 tremities of roots. When we dissect these extremities, 

 we only find in the interior round cellular tissue ; but 

 although the entire body of each radical fibril appears 

 composed of an analogous cellular tissue, experience 

 proves that it is by the extremity alone that the 

 absorption of the sap is performed. In fact, if we 

 place, as Senebier did, two roots in such a manner, 

 that in the one the extremity alone touches the water. 



