Mr. A. Henfrey on the Progress of Physiological Botany. 49 



V. — Reports on the Progress of Physiological Botany. No. I. 

 By Arthur Henfrey, F.L.S. &c.* 



Recent researches into the origin and development of the Vegetable 



Embryo. 



This " vexed question," on which botanists in general have of 

 late years been unable to form a satisfactory opinion, so contra- 

 dictoiy and well-balanced has been the evidence for the various 

 hypotheses, appears now somewhat nearer to a decisive settlement, 

 since within the last year we have had no less than four elaborate 

 and comprehensive essays presented to us, detailing the whole 

 series of changes which the ovule passes through, from the open- 

 ing of the bud to the ripening of ihe seed. When the names of 

 Amici and Von Mohl appear as the authors of two of these papers, 

 it will be understood how important these new investigations are ; 

 and the fact of the agreement of all four inter se, excepting in 

 some trivial points, and the possibility of reconciling their results 

 with the appearances which have presented themselves to authors 

 holding different views, will probably cause them to be regarded 

 as tolerably conclusive. The great result at which all these 

 recent writers have arrived is, that Schleiden's statement, that 

 the end of the pollen-tube becomes the embryo, is incorrect, and 

 that the old opinion, which regarded the pollen as the source of 

 a fertilizing matter necessary to stimulate the embryo-sac to the 

 development of the germ of the future plant, is true ; the pollen- 

 tube being consequently merely the agent for the conveyance of 

 the fertilizing matter through the style and the foramina of the 

 ovule, having its progress arrested upon the outside of the wall 

 of the embryo-sac, through which and the membrane of the 

 pollen-tube itself the fecundating fluid is supposed to be im- 

 bibed. 



The few remarks which it may be necessary for the reporter 

 to make on the relations of these investigations to preceding ob- 

 servations, will be most conveniently reserved till after a general 

 account of them has been laid before the reader. 



The first paper we meet with is one read by Prof. Amici before 

 the Italian Congress at Genoa in 1846. Our knowledge of it is 

 derived from German and French translations*. 



In the first instance the author refers to some observations 

 previously made public upon Cucurbiia Pepo, in which he showed 

 that the pollen-tube penetrates into the neck or summit of the 

 nucleus to a certain depth, but never into the embryonal vesicle f, 



On the Fertilization of Orchidacece, by Prof. J. B. Amici, Giornale Bo- 

 _aico Italiano, di Filippo Parlatore. (Transl. Ann. des Sc. Nat. 3 ser, vii. 

 13, April 1847 ; and by Von Molil, Hot. Zeitung, May 21 & 28, 1847.) 

 [f By embryonal vesicle Prof. Amici signifies the embryo-sac, and this must 



%n. ^ Mag. N. Hist. Ser. 2. Vol. i. 4 



