I 



[ 69 ] 



II. On the Development of the Ovule of Santalum album ; with some Remarks on the 

 Phcenomena of Impregnation in Tlants generally. By Arthur Henfeey, Esq., 

 F.B.S., F.L.S., Prof of Botany in King's College, London. 



Read March 4th, 1856. 



In the 21st volume of this Society's " Transactions" are published the results of some of 

 my earliest observations on the phaenomcna of fertilization and development of embryos 

 in flowering plants. To myself, these were at that time conclusive, and they were in 

 accordance with those published shortly before by Amici, von Mohl, and Miiller, sub- 

 sequently confii'med, with far more extensive illustration, by Hofmeister and Tulasne. In 

 spite of all the adverse evidence, however, Schleiden still continues to maintain the doc- 

 trines he formerly propounded, and during the last few years he has found a most active 

 supporter in Sehacht. 



Those who have not directed their labours to the practical examination of these delicate 

 points, may feel surprise at the discrepancy existing between the statements of different 

 observers. Those who have been engaged in the dissection of ovules in the earher stages 

 of development, will not much wonder at doubts arising in my mind whenever I have 

 met with statements directly contradicting those made in my former paper. The number 

 of instances in wliich a satisfactory observation is made, is very small in comparison with 

 the number of specimens examined; and notwithstanding that I have year after year 

 devoted much time to the dissection of ovules, these time-devouring researches have 

 yielded me a far smaller number of facts than I could wish. 



A certain amount of discrepancy exists even between the statements of the disciples of 

 Amici, in regard to the origin of the germinal vesicle [Keimbldschen) ; and to whether it 

 exists before, or is formed after fecundation. Hofmeister* says before; Tulasne t says 

 he never could find it anterior to the fertilization. The latter, in the memoir just referred 

 to (page 115), adds, "This delicate question no longer (1849) perhaps possesses all the 

 interest which was accorded to it by MM. Mirbel and Brongniart, and more recently by 

 Mr. A. Henfrey, in his 'Report on the Progress of Physiological Botany J.' It is true, 

 the existence of the embryonary vesicle at a period anterior to the arrival of the pollen- 

 tube would, if placed beyond doubt, prove invincibly that this vesicle could not owe its 

 origin to the latter organ ; even now that the ereor of the pollinists is no longer uncer- 

 tain, the question seems to me worthy of the attention of botanists, especially on account 

 of the theoretical consequences involved in its solution." 



Confidently as Tulasne expressed himself as to the origin of the germinal vesicle inde- 



* Entstehung der Embryo. Leipsic, 1849. f Annal. des Sciences nat. 3°" 8(Sr. xii. p. 1 14. 



X Ann. Nat. History, ser. 2. i. p. 49 (1848). 



