STRUCTURE OF FRUIT. 149 



stance so modifies their form and appearance, that it is 

 necessary to describe it in detail. That fruits with 

 several cells placed horizontally are composed of carpels 

 united together, is what, I think, cannot appear doubt- 

 ful to any one who has attentively studied the article 

 upon the Pistil in the preceding Chapter. Some exam- 

 ples seem to render this fact more particularly evident ; 

 thus, among the Helleboreae, we find some with the 

 carpels perfectly free, such as Aconitum, whilst in certain 

 genera, as Nigella, we find species where the carpels are 

 united at the base only, as iV. orientalis : others, where 

 the union proceeds half-way, as N. saliva, and others 

 where they are united nearly to the apex, as in 

 N. Damasccena. It is the same in the Apocyneas and 

 Asclepiadeae, in which we find all the gradations, from 

 the perfectly free carpels of Asclepias, to those of Cer- 

 bera, Rauwolfia, &c. which are united into an apparently 

 simple fruit. Similar examples are found in a great 

 number of families. 



We have already found, in these facts, a very simple 

 explanation of what was, or ought to be meant in 

 speaking of entire, divided, parted, and compound fruits. 

 Entire ones are those where the carpels are united 

 throughout their whole length ; divided ones, where the 

 union only proceeds half-way ; parted ones are those 

 where the carpels are only united at the base ; com- 

 pound ones, where the carpels are free from all cohesion. 



In fruits with the carpels united throughout their 

 whole length, there may also be several cases : the 

 carpels either have the ventral suture prolonged more in 

 proportion than the dorsal, and then the whole fruit is 

 more or less pointed at the base, or vice versa, and then 

 the fruit is necessarily lobed at the summit: or, lastly, 

 the two sutures are perceptibly equal, and then the 

 fruit is obtuse or truncated. Thus, all the longitudinal 



