2'J2 



A TEXT-BOOK OF BOTANY. 



Conducting cells or mestome Include those cells which are 

 chiefly concerned in the transferral of either crude or assimilable 



Fig. 142. Development of spiral bands in the mechanical cells of young fruits of Fegatella 

 conica (Hepaticae): I, young cell with vacuoles and small starch grains; II, portion of an older 

 cell showing formation of large vacuoles in the protoplasm, the strands of which are arranged 

 in a left-hand spiral; III, showing spiral arrangement of protoplasm; IV, portion of cell 

 as in III treated with a sugar solution and showing plasmolysis of protoplast; V, showing 

 formation of band; VI, a cell as in V treated with sugar solution, sho-ving the protoplasm 

 arranged along the thickened portions of the wall where the bands are forming; VII, the 

 mature cell showing lignified spiral bands. — After Dippel in "Das Mikroskop." 



food materials. The more or less crude inorganic materials are 

 carried from the root through the woody portion of the stem to 



