named R.\ rri.r.si \. 217 



minn of certain Aroidea, in which it has been observed that a con- 

 tinued secretion and discharge of pollen takes place from the same 

 cell ; the whole quantity produced greatrj exceeding the size of 



the secreting organ. 



The passage of the pollen to the bottom of the Bower, where it 

 is more easily accessible to insects, seems likewise to be pro- 

 vided for, not only l>\ the direction of the anther®, but also b\ 

 the form of the corresponding cavities in the neck of the column, 

 in the upper part of which thej are immersed. 



That insects are really necessary to the impregnation ot* luij- 



flesia, is confirmed by \h\ Arnold's statement respecting the odour 



of the plant, b\ which they may be supposed to be attracted, and 



also by the fact of the swarms actually seen havering about and 



tling in the expanded flower. 



The structure of Rajflesia is at present too imperfectly known 

 to enable us to determine its place in the natural system. I shall, 

 however, offer some observations on this question, which can 

 hardly be dismissed without examination. 



As to which of the two primary divisions of plnenogamou> 

 plants the genus belongs, it may, I think, without hesitation 

 be referred to Dicotyledones ; yet if the plant is parasitic, and 

 consequently no argument on this subject to be derived from the 

 structure of the root, which is exactly that of the Vine*, its 

 exclusion from Monocotyledones would rest on no other grounds, 

 that I am able to state, than the quinary division of the perian- 

 thium, which in other respects also bears a considerable resem- 

 blance to that of certain dicotyledonous orders ; the number of 

 stamina, and the ramification of vessels in the bracteac. 



Assuming, however, that Rajflesia belongs to Dicotyledones, 



* Compare the magnified section of the Root, tab. 22. f. 8. with that of the Vine 

 in Grew's Anat. tab. 17- 



vol. xiii. 2 e and 



