THE UMBELLIFER^;. 



mericarp. Five ridges are seen passing from bottom 

 to top of each mericarp, and often four intermediate 

 or secondary ones, which may be, some, none, or 

 all of them, winged. In the substance of the thin 

 pericarp are little bags of colored oil, called vittce, 

 that give aromatic and stimulating properties to all 

 the plants of this family. Four of these bags are 

 seen in Fig. 311, in the intervals of the ribs. In the 



FIG. 310. 



FIG. 811. 



FIG. 312. 



Cremocarp of 



two Carpels, each 



of which is a 



Mericarp. 



Mericarp. 



Cross-section of a Mericarp. 



cross - section of a mericarp (Fig. 312) the little 

 mouths of the four oil-bags of the back are seen, 

 along with two others, in the face of the commissure. 

 If you have difficulty in finding these oil-bags, cut 

 the carpel across, as shown in Fig. 312, and look 

 down upon it with your glass, and perhaps their cut 

 ends will be visible to you. A thin section, moist- 

 ened and seen under a microscope, reveals them very 

 distinctly. 



Collect all the plants you can find with this kind 

 of inflorescence, and examine their flowers and fruit. 

 In most cases you will need your glass and much 

 patience in doing this ; but, if you cannot discover 



