[3 
IL. On the Development of the Ovule of Santalum album; with some Remarks oh the 
Phenomena of Impregnation in Plants generally. By ARTHUR sa 
F.R.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 phenomena 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 Miller, sub- 
sequently confirmed, 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 Schacht. : 
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 earlier 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 which 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. 
Å certain amount of discrepancy exists even between the statements of the disciples of 
Amici, in regard to the origin of the germinal vesicle (Keimbläschen) ; and to whether it 
exists before, or is formed after fecundation. Hofmeister* says before; Tulasnet 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 eF recently by 
Mr. A. Henfrey, in his * Report on the Progress of Physiological Botany f 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 error of the pollinists on — Boe 
tain, the question seems to me worthy of the attention of botanists, especially on accoun 
of the theoretical consequences involved in its solution." : Re 
Confidently as Tulasne expressed himself as to the origin of the germinal vesicle inde- 
: i . 9"* ser, xii. p. 114. 
* Entstehung der Embryo. Leipsie, 1849. fn du Dámon sat, Svr e p 
t Ann. Nat. History, ser. 2. i. p. 49 (1848). 
