202 



THE SECOND BOOK OF BOTANY. 



stringy pulp ID a little water, and separate from it 

 some of its smallest threads. Put these on the glass 

 with a drop of water, and arrange the thin cover as 



FIG. 364. 



FIG. 365. 



before. "When magnified, you will see among the 

 cells long, tube-like bodies, having their walls marked 

 with rings and spirals, such as are shown in Fig. 364. 

 Examine slices taken both across and 

 lengthwise from the young, succulent, fast- 

 growing shoots of any plant ; from the ribs, 

 petiole, or veins of leaves ; from parts of 

 the flower, of roots, or of underground 

 stems. By carefully looking at these sec- 

 tions, you will again see embedded among 

 the cells tubes of varying length, and with 

 different aspects. These tubes are called 

 ducts. 



EXPERIMENT. Take a small bit of soft 

 wood, half the size of a pea, and boil it in 

 a few drops of nitric acid for several sec- 

 onds. Rinse it carefully with water three 

 or four times, to cleanse it from acid, and 

 pick it to pieces, as you did the fibre of 

 rhubarb. Examine a minute portion of 

 this wood under the microscope. You will 



