1843.] Linnean Society. 169 



In this paper, dated " Malacca, March 28th, 1842," Mr. Griffith 

 proposes to supply many of the deficiencies in his tv/o memoirs on 

 the ovula of Santalum, Loranthus and Viscum, published in the 1 8th 

 vol. of the Society's " Transactions," to correct some important mis- 

 takes, and to extend his inquiries to another genus of the natural 

 family of Santalacea, viz. Osyris. With this view he gives a detailed 

 description of the progress of the development of the embryo, so far 

 as he has been enabled to observe it, in Santalum album, Osyris Ne- 

 palensis, Loranthus bicolor, Loranthus globosus and tvv^o species of 

 Viscum ; each of which subjects is illustrated by an extensive series 

 of microscopical drawings. In connection with these details he pro- 

 ceeds to remark at some length on the four following points : — 1. the 

 solidity of the ovarium and the appearance of the ovulum after fecun- 

 dation, or rather after the action of the pollen on the stigmatic sur- 

 faces ; 2. the reduction of an ovulum to the nucleus or to the 

 embryonary sac ; 3. the embryonary sac ; and 4. the origin of the 

 embryo. The following is the summary given by him of his ideas 

 of the structure of Santalum, Osyris, Loranthus and Viscum : — 



" In Santalum the ovulum consists of a nucleus and an embryonary 

 sac, prolonged beyond both the apex and base of the nucleus : the 

 albumen and embryo are developed in the parts above the septum 

 [in the exserted portion of the sac] , the parts below and the nucleus 

 remaining unchanged. The embryo is developed from the poUinic 

 vesicle. The seed has no actual proper covering, and no other theo- 

 retical covering than the incorporated upper separable parts of the 

 embryo-sac. 



" In Osyris the ovulum is reduced to a nucleus and an embryonary 

 sac, which is prolonged in the same directions as in Santalum, but not 

 to such a degree beyond the apex of the nucleus. The seed is formed 

 outside the embryo-sac, and is absolutely without proper tegument, 

 or whatever covering it may have did not enter into the composition 

 of the ovulum. The embryo appears to be developed at some di- 

 stance from the anterior end of the pollen tube. 



" In Viscum the modifications appear to me to be two : in the one 

 an evident cavity exists in the ovarium, and the ovulum appears to be 

 reduced to an embryonary sac hanging from one side of the base of 

 a nipple-shaped or conical placenta. In the other the ovulum is 

 reduced to an embryonary sac, but this is erect, and has no such ob- 

 viously distinct point of origin as in the first. In both the albumen 

 has no other proper covering than the incorporated embryonary sac ; 

 and, at least in the last, the embryo appears to be a direct transfor- 

 mation of the poUinic vesicle. 



No. XVIII. — Proceedings of the Linnean Society. 



