a7id certain Indian Terebinthaceœ. 359 



If the attempt is to be at present made, the most obvious 

 ground which coukl be immediately proposed, is that which was 

 rejected by Willdenow ; the presence and form of the nectary or 

 disk encompassing the ovary. In many species of Amyris it is, 

 as a nectary or ghmduhir ring, wanting ; being only shadowed 

 or represented by a fleshy receptacle or continuous podogynium 

 elevating the germ and receiving the filaments and petals in- 

 serted in its foot. In other instances the nectary is clearl}^ pre- 

 sent, consisting in a glandular ring, which girds the base of tlie 

 germ, distinct from the receptacle beneath it, in which the sta- 

 mina and petals are inserted. It is discriminated from that by 

 a difference of form and appearance, or more simply separated 

 by a contraction or intermediate strangulation. In some in- 

 stances the annular receptacle of the germ or nectarial ring is 

 crenulate ; in others it is distinctly glandular ; in a few it is 

 merely protuberant. 



The total absence of a nectary, and consequent restriction of 

 the common receptacle of stamina and petals below and germ 

 above to a simple podogynium, might serve to characterize one 

 group in this family. Many species of Ami/ ris belong to it: 

 among them may be enumerated several Indian sorts, as A. nana, 

 A. acuminata, and A. ptntaphylla of Roxburgh. 



A crenulate ring occurs in Bnrsera serrata ; and this form of 

 the nectary intimates analogy with BosweUia, which has a crenu- 

 late fleshy cup, in the exterior margin whereof the stamina are 

 inserted. That analogy is strengthened by the examination of the 

 seed, which exhibits in both instances multilobed and intricately 

 folded cotyledons. '1 he presence of a crenulate nectary, there- 

 fore, mioht be taken for the discriminative mark of one more 

 group, — a link in the chain from the first-mentioned towards 

 BosweUia. 



Intermediately occurs another, in which the nectary is present 

 VOL. XV. 3 a but 



