304 Mr. Griffith on the Root-Parasites referred to Rhizanthese, 



indeed, in the preface to their 'Prodromus Florae Peninsulse Indiee Orientalis,' 

 p. xxxi, mention an objection, founded on certain instances of conferru mi na- 

 tion of those parts of an embryo that are usually distinct. But this, in my 

 opinion, by no means constitutes a " perfectly simple seed like that of Acoty- 

 ledoncs" and cannot be brought to bear upon a question, which has a very 

 especial reference to the absolute absence of the usual form of the vegetable 

 embryo. 



I have frequently been tempted to make the paper more complete, or at 

 any rate more pleasing to myself, by giving the characters of the undescribed 

 natural families contained in the Rhizanthece of Endlicher and Lindley, and 

 which I might have taken to be represented by Thismia, Sarcophyte, and 

 perhaps Mystropetalum ; and though these might not have been adopted, I at 

 least might, have always abided by them and quoted them. But, independ- 

 ently of my not having had opportunities of examining many of the genera 

 thrust into Rhizanthece, it appears to me that such an attempt would have 

 been very premature in the absence of information regarding the important 

 physiological functions of impregnation and germination. I would in all 

 cases rather be the doubtful, questioning indicator, than the confident fabri- 

 cator of a group, of which we have but very imperfect knowledge. 



Obs. I.— The points in which the plants constituting the Rhizanthece are 

 said to agree, are : 



1. Parasitism. 



2. Defective vascularity. 



3. Homogeneous or anembryous sporuliferons seeds. 



They are also generally unisexual, and of a fungoid or volvuloid mode of 

 evolution (development). 



M. Endlicher and Dr. Lindley appear to place most reliance on the second 

 and third points of resemblance: yet it appears to me that there is not one 

 which does not present important structural variations. 



1. The parasitism can only be said to be constant in its effects, which are 

 similar to those observed to occur (almost) constantly in all Phamogamous 

 plants parasitic on roots. For there is a wide difference, it appears to me, 

 between the parasitism of Sapria, Cytinus, and very probably of Rafflesia, 

 and that of Balanophora and Phceocordylis, which appears to me to be of a 



