OF STIPULES. 



389 



All the moDopetalous stipulate orders have opposite leaves. 



Of the former, four have Ficoid stipulte, two inter petiolar stipu- 

 lae ; but of these, one is occasionally ex stipulate, two have scarious, 

 one ochreate, and one axillary slipulse. The remainder have sti- 

 pulse verae. 



Of raonopetalous stipulate orders, three have inter petiolar sti- 

 pulo9, this form it may be remarked, presumes the existence of op- 

 posite leaves. 



Ovarium adnatum exists in 10 of the polypetalous stipulate or- 

 ders, and in one of the monopetalous, but of the former, two have 

 genera with superior ovaria. 



Of the former, 19 have perigynous stamina, but in one of these, 

 Vochyaceae, genera occur with hypogynous stamins. 



Definite stamins occur in 30, but of these, three have, definite or 

 indefinite, and in all of the stipulate monopetalous orders, definite 

 stamins occur. 



Albumen occurs in all of these latter, and in 28 of the former, 

 but its presence in six out of these, is not universal. 

 ' The only conclusions to be arrived at are, that stipulte are almost 

 exclusively confined to Dicotyledones, and that they are much more 

 frequent in such of these as have their petals distinct. 



The functions of these appendages are, either simple or com- 

 pound, and they may be divided into two classes. 



1st. Stipulaj versa, which are always inserted on the same plane with 

 the petiole, with which they always have some connection. Their 

 functions being generally to increase the surface of the green pa- 

 renchyma, at least when they are well developed. The ratio of 

 these to those of the succeeding class, including both polypetalous 

 and monopetalous, is as one to seven. 



2nd Stipulae tegentes, which in addition to that of increase of 

 surface, perform the function of tegmina of buds, this includes the 

 Ficoid, inter-petiolar, and ochreate forms. But it is very probable 

 that many of these, as for instance those of Ficus, and Dipteroearpus, 

 have no stomata. The stipulae of this class frequently arc not in- 

 serted on the same plane with the leaves, especially in some Rubi- 

 ace£e, and in Dipteroearpus ; still they can scarcely be looked upon 

 as forming a distinct series of leaves, since the parts which they 

 protect are regulated by laws having reference to the leaves 

 themselves, and not to the stipulae as would otherwise be the case. 



