208 Mr. Griffith on the Ovulum o/'Santalum, 



did, and the circumstances I have detailed regarding it are not, I think, in- 

 consonant with analogy. 



The objection deducible from some parts appearing, when separated, to 

 present an entire edge, may be waived on the score of the minuteness of the 

 observation which would relate to a cicatrix or scar of separation of an undi- 

 lated part of the pollen tube. Besides, I would be by no means disposed to 

 deny that a plant may have the power of closing up such a solution of con- 

 tinuity, as must be admitted to have occurred, if my opinion of the origin of 

 this vesicle be correct. 



So far as the other instances which I have endeavoured to illustrate are con- 

 cerned, more exact inquiries are very necessary, particularly as regards the 

 origin of the albumen in Osyris and the relations of its young embryo to the 

 pollen tubes. As regards Loranthus, further observations are required on the 

 state of the pollen tubes intermediately between their penetration into the sac 

 and continuation beyond it : on the state of the embryo-sacs at the time the 

 pollen tubes are continued beyond them : on the degree to which the embryo- 

 sacs of L. bicolor may develope albumen in their interior, and those of L. glo- 

 hosus above that part of the sac in which the albumen first makes its appear- 

 ance. Lastly, as regards Viscum, especial inquiry is requisite concerning the 

 origin of the ovulum — this holds good equally with those of Loranthus — and 

 the direct conversion of the pollinic vesicle into the embryo. 



The materials for all these, excepting Santalum itself, perhaps, exist in the 

 immediate neighbourhood of Malacca. 



Malacca, March 28, 1842. 



EXPLANATION OF THE PLATES. 



[The figures given in the five plates accompanying Mr. Griffith's Memoir 

 have been selected from a very extensive series of drawings forwarded by him 

 from Malacca, as those which appeared best calculated to illustrate the struc- 

 ture of the plants examined, and the views entertained by the author regarding 

 them.] 



