363 Dr. L. Radlkofer on Fecundation in the Vegetable Kingdom, 



1850) detected the germinal vesicle long before the bursting of the 

 anthers, but only a single one. From this, after fecundation, he saw 

 produced the suspensor and embryo. 



H. Criiger ('Befrucht. bei den Orangen,' Bot. Zeit. 1851, p. 57) 

 placed himself decidedly in opposition to Schleiden. His observa- 

 tions, however, were by no means complete ; in particular, he did 

 not detect in the unfecmidated embryo-sac the germinal vesicles, of 

 whose presence recent reseaixhes leave me in no doubt. 



W. Hofmeister, in his memoir on Zostera (Bot. Zeit. 1852, p. 121, 

 and Taylor's Scientific ]Memoirs, ser. 2. Nat. Hist. i. p. 239, 1853) 

 adds to his numerous earlier researches a new history of development 

 of the embryo, agreeing perfectly with his former account. 



Postscript. — I make use of this opportunity to report on certain 

 memoirs which, either more recent or of the same date as my own, 

 have come into my hands since that was printed. 



Schacht has pubhshed new researches ' On the Origin of the Em- 

 bryo in TropcBohun majus' (Bot. Zeit. 1855, p. 641; Ann. des Sc. 

 nat. 4 ser. iv.). He here detected the germinal vesicles in the un- 

 fecundated embryo-sac, but was of opinion that they disappeared 

 again at the time when the pollen-tube entered the micropyle. He 

 regarded the fecundated germinal vesicle, which he detected at a 

 subsequent period, as a totally different structure from the first — 

 namely, as the immediate prolongation of the pollen-tube. 



Th. Deecke (* Entwickl. der Embryo der Pedicidaris sylvatica' 

 Bot. Zeitung, 1855, p. 657; Ann. des'Sc. nat. 4 ser. iv.) endeavoured 

 to answer Hofmeister' s objections to the interpretation given by 

 himself and Schacht to his much-discussed preparation, and to 

 strengthen his reasoning with the results of new investigations. I 

 was indebted to the kindness of Th. Deecke for an opportunity of 

 examming this preparation, and of acquiring a positive conviction as 

 to the condition of the anterior end of the embryo-sac. I perceived 

 not merely the two lines which Schacht has drawn as running 

 away from the pomts of contact of the lateral boundary -lines of the 

 embryo-sac and suspensor, and uniting below in an angle projecting 

 downwards, — but also two others, which (as nearly as I can describe 

 their positions) passed from the same points, each running about 

 parallel to the lines drawn by Schacht on the othei' side, thence 

 uniting <at angles projecting upwards. These two lines, therefore, 

 with the two drawn by Schacht, bounded an almost rhomboidal hole, 

 which, from the condition of its edges, was doubtless artificial ; one 

 section of this (I do not recollect exactly whether the lower (figured) 

 or upper one) being over, the other under the suspensor which had 

 been dra\\Ti forward out of it. 



With regard to Th. Deecke's newer preparations, on which pi. 10 

 is based, several of which also he was kind enough to show me, 

 what I observed agrees no better with his drawings ; for example, in 

 the preparation drawn in fig. 6, I saw, in the space which exists in 

 the drawing between the end of the suspensor {t, p) and what is 



