EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



433" 



The febrifugal properties of the former depend on the presence of 

 two alkaloids, Cjjic/iom'a and Quinia, both combined with Kinic acid. 

 The Quinquina barks, which are derived from some species of Ex- 

 ostemma and other West Indian, Mexican, and Brazilian genera, 

 contain neither cinchonia nor quinia. The bark of Pinckneya pu- 

 bens, of the Southern United States, has been substituted for Cin- 

 chona. — The true Ipecacuanha is furnished^ by the roots of Cepha- 

 aslis Ipecacuanha of Brazil and New Granada. Its emetic principle 

 (called Mmetine) also exists in Psychotria emetica of New Granada, 

 which furnishes the striated, black, or Peruvian Ipecacuanha. The 

 order likewise furnishes Coffee, the horny seed (albumen) of Coffa^a 

 Arabica. According to Blume, the leaves of the Coffee-plant are 

 used as a siibstitute for tea in Java. — To this order may be ap- 

 pended, either as a suborder, or, as in a general work it is more con- 

 veniently regarded, the 



841. Ord. LoganiaceSB, which may be briefly said to be Eubiacese 

 with a free calyx, and manifestly connected with the Cinchonese 

 through the Houstonia section of Oldenlandia, with a partly free 



FIG. 872. OldenlaDdia (HouBtonia) casrulea. 873, 874 The two sortsof flowers that differ- 

 ent individuals bear, with the corolla laid open ; one with the stamens at the base, the other 

 at the summit of the tube : the lower figure shows also a section of the ovary. 875. Cross- 

 section of an anther, magnified. 876 Anther less enlarged, opening longitudinally. 877. 

 Capsule with the calyx. 878, 879. Views of the capsule in dehiscence. 880. Diagram of a 

 cross-section of the unexpanded flower. 



37 



