IN EXTRA-TROPICAL COUNTRIES. 73 



The thickest bark is obtained in the highest altitudes, which by 

 passing clouds are often involved in misty humidity (Cross). 



Cinchona micrantha, Ruiz and Pavon. 



Cordilleras of Bolivia and Peru. This tree attains a height of 

 60 feet, and from it part of the Grey and Huanuco Bark, as 

 well as Lima Bark, are obtained. It is comparatively rich in 

 cinchonin and quinidin ; contains, however, also quinin. 



Cinchona nitida, Ruiz and Pavon. 



Andes of Peru and Ecuador. This tree rises to 80 feet under 

 favourable circumstances. It also yields Grey Bark and Hua- 

 nuco Bark, besides Loxa Bark. It will probably prove one of 

 the hardiest species. It contains predominantly cinchonin 

 and quinidin. 



Cinchona officinalis, Linne* (partly).* (Cinchona Condaminea, 

 Humboldt). ' 



Andes of New Granada and Peru, at a height of 6,000 to 

 10,000 feet. Yields Crown or Brown Peru Bark, besides part 

 of Loxa Bark. Comparatively rich in quinin and cinchonidin. 

 The temperature of the middle regions of the Andes, where 

 this tree grows, is almost the same as that of the Canary 

 Islands. Superabundance of moisture is particularly perni- 

 cious to this species. The Crispilla variety endures a tempera- 

 ture occasionally as low as 27 F. 



Cinchona lancifolia (Mutis) is considered by Weddell a variety 

 of C. officinalis. This grows on places where the mean annual 

 temperature is that of Rome, with, however, less extremes 

 of heat and cold. It yields part of the Pitaya Bark. 



Cinchona Pitayensis must also be referred to C. officinalis as 

 a variety. This attains a height of 60 feet and furnishes also 

 a portion of the Pitaya Bark. It is this particular cinchona 

 which in Upper India yielded in some instances the unprece- 

 dented quantity of 11 per. cent, alkaloids, nearly 6 per cent, 

 quinin, the rest quinidin and cinchonin ; this plant is now 

 annihilated for bark purposes in its native forests. 



In Java some of the best results were obtained with Cinchona 

 Hasskarliana, Miq., a species seemingly as yet not critically 

 identified. 



Cinchona succirubra, Pavon.* 



Middle Andine regions of Peru and Ecuador. A tree attaining 

 a height of 40 feet, yielding the Red Peru Bark, rich in quinin 

 and cinchonidin. It is this species which is predominantly 



