162 UMBELLIFER.E. [CLASS 



Natural Order, it is necessary to devote some careful 

 attention to it. It is always inferior, and consists of 2 

 carpels, applied face to face. The entire fruit is termed 

 a cremocarp, each of the carpels a mericarp. The meri- 

 carps are popularly called "seeds," as Caraway-seeds, 

 &c. You will, of course, note that each mericarp consists 

 of seed and pericarp. 



FIG. 112. One of the mericarps of the fruit of Common Heracleum, seen 

 from the back, showing four vittse. 



The plane of union of the two mericarps is called the 

 commissure. The pericarp is frequently marked with 

 ridges : of these ridges, 10 are primary, viz. 5 answering 

 to the lines of union of the 5 sepals which form the 

 calyx, and 5 to the midribs of the same. The former, or 

 suluml ridges, are opposite to the petals ; the latter, or 

 carinal ridges, are opposite to the stamens. These ridges 

 are disposed in such a way that each mericarp bears 5 : 

 on one mericarp 3 carinal and 2 sutural ridges ; on the 

 other, 2 carinal and 3 sutural ridges. 



Secondary ridges rise, sometimes, in the interstices of 

 the primary ridges. 



Figure 113 represents a cross section of one of the 

 mericarps of Cow-Parsnip. The structure of the fruit 

 cannot be made out satisfactorily without examining it 

 thus cut across. Embedded in the substance of the thin 

 pericarp, longitudinal canals often occur, containing 



