ORDER CAMPANULACE^, OR HAIRBELL TRIBE. 467 



carpels generally commences, that part is found to be even 

 tougher than the sides ; but Nature has provided another very 

 simple means for the exit of the fruit, by the rending of the ova- 

 rium (when every part of it becomes stretched so tight in drying, 

 that some part of it must necessarily give way) at its sides, 

 between the ribs, where the skin is weakest. The rent takes 

 place in such a manner, as to leave a large orifice to each cell, 

 through which the seeds are readily scattered. 



639. A large proportion of the plants of the Hairbell tribe 

 are as harmless as they are beautiful ; the roots of some species 

 are eaten under the name of Rampion ; the leaves of others are 

 used in Salads ; and the bells afford an abundant supply of honey 

 to the Bee. The stem and roots abound in a milky juice (another 

 character of alliance to the Cichoracese), which does not possess 

 any deleterious properties. There is a subdivision of the group, 

 however, of which a separate order has been formed by some 

 Botanists under the name of Lobeliace^ the Lobelia tribe, which 

 is distinguished for its extreme acridity. The species belonging 

 to it are known by the irregular form of their corolla, which has 

 some resemblance to the ligulate florets of the Composite ; and 

 also by the partial cohesion of their anthers ; so that they 

 approach the Compositse still more decidedly than do the true 

 Campanulaceae. A character of much interest (which, however, 

 can only be distinguished with the aid of the microscope) is, that 

 in the true Campanulacece the pollen grains are round, whilst in 

 the Lobeliacece they are oval. The plants of the latter group are 

 most abundant in countries bordering on the tropics. Only two 

 species are natives of England ; but many more have been intro- 

 duced into our gardens, where they are valued on account of the 

 beauty of their flowers. One species, the Lobelia inflata, a native 

 of North America, has been used in medicine as an emetic and 

 expectorant, and has been accounted a most important remedy 

 for Asthma ; it is very uncertain, however, in its effects, and 

 has produced fatal consequences when given in an overdose. 



640. The last order of Calycifloral Exogens which will be 

 here noticed, is that of ERICINEJE, the Heath tribe, a group of 

 extreme beauty, which is easily recognised by certain peculiar!- 



