200 Mr. Griffith on the Ovulwn o/*Santalum, 



give my own a better claim perhaps to notice. With the exception of this, 

 and such part of my own observations as would refer the embryo, for the 

 greater part, or perhaps entirely, to a growth from the ends of the pollen 

 tubes, except in Fiscum, I cannot but hope that these present observations 

 will be considered to be striking corroborations of the general views of 

 M. Schleiden. Of M. Wydler's observations I have no knowledge but that 

 very lately derived from an able summary by Dr. Giraud of the recent doc- 

 trines of vegetable embryology in the c Annals of Natural History/ No. 31, 

 June 1840, and which therein only go so far as to establish the points of non- 

 inflection of the sac, and of the entrance of the pollen tubes into it. On the 

 general subject of the vegetable ovulum I hope to enter into detail as soon 

 as the proper opportunities offer, not so much in the hope of producing any- 

 thing new on a subject on which Mr. R. Brown, and MM. Schleiden, Mirbel 

 and Brongniart have been engaged, but to extend the application of the facts 

 established by them to plants out of the reach of European savant. 



The growth of a tissue from the ends of the pollen tubes, from which tissue 

 the embryo of Loranthus is directly formed, appears to me to open to view 

 glimpses of the most beautiful analogies. 



In the sporula, so called, of the more developed Acotyledonous plants, we 

 have organs consisting of two envelopes ; the inner of which contains granular 

 matter, has remarkable powers of growth, and, so far as function is concerned, 

 appears to be alone essential. The proper stimulus calls this membrane into 

 growth, and from the apex of its extension cells are developed ; from these 



^ZZZZ " r° dUCed; and ^ thG CCntre ° f the mass *« formed, 

 originates at a certain period the growth of the true axis 



Plamf witt Z7; ^^ ^r " thG f ° rmati0n ° f thG Seed * f Ph-ogamous 



t rlid I" 6 ' thG albUmen ' ^^ ^ ha P S th * *"L* ^ 



the Acotyledonous plant, is not a direct growth from the pollen tube Such 



other differences as appear to exist it-p ^f • 



the different nature o 'be tZZ^L^T'"'' ' ** ""** " 



-.nbrane, in the eonden* J* t^^l * *? "T^ * *"" *" 



be reasonably inferred to arise f o „ th ™ fi 7?* ^ "^ ^ may 



ause ttom the confined situation in which they 



* Am I right m the use of the term thallus ? by which I m ra n «. 

 the germination of Acoty.edo„„„ s plants , such , J;,,^ £££?"* ■" fat *"■"* » 



