STRUCTURE OF PLANTS. 331 



Is it not probable that they facilitate absorption of the juices 

 carried back from the leaf for the nutrition of the stern 

 and roots ] They are admirably adapted for performing 

 this office. Their component fibrous cells, having angles 

 insinuated between the cells of the parenchyma, are shaped 

 just as they should be for taking up its contents, and the 

 absence of sheathing tissue between them and the paren- 

 chyma facilitates the passage of the elaborated liquids. 

 Moreover, there is the fact that they are allied to organs 

 which obviously have absorbent functions. I am indebted 

 to Dr. Hooker for pointing out the figures of two such 

 organs in the Icones Anatomicce of Link. One of them 

 is from the end of a dicotyledonous root-fibre, and the other 

 is from the prothallus of a young fern. In each case a . 

 cluster of fibrous cells, seated at a place from which liquid 

 has to be drawn, is connected by vessels with the parts to 

 which liquid has been carried. I have met with another 

 such organ, more elaborately constructed, evidently adapted 

 to the same office, in the common turnip-root. As shown by 

 the end view and longitudinal section in Nos. 3, 5, and 8, 

 this organ consists of rings of fenestrated cells, arranged 

 with varying degrees of regularity into a funnel, ordinarily 

 having its apex directed towards the central mass of the 

 turnip, with which it has, in some cases at least, a traceable 

 connexion by a canal. Presenting as it does an external 

 porous surface terminating one of the branches of the vas- 

 cular system, each of these organs is well fitted for taking 

 up with rapidity the nutriment laid by in the turnip-root, 

 and used by the plant when it sends up its flower-stalk. 

 The cotyledons of young beans furnish other examples 

 of such structures, exactly in the places where, if they be 

 absorbents, we may expect to find them. Amid the 

 branchings and inosculations of the vascular layer running 

 through the mass of nutriment deposited in each coty- 

 ledon, there are found conspicuous free terminations that 

 are club-shaped, and which prove to be composed, like 

 those in leaves, of irregularly-formed and clustered fibrous 

 cells, some of them diverging from the plane of the vascular 

 layer, dipping down into the mass of starch and albumen 

 which the young plant has to utilize, and which thesa 

 structures can have no other function but to take up." 



