130 MR. HENFREY ON THE DEVELOPMENT 



fig. 80, where the ragged tissue (h) is seen to he the torn edge or collar always found 

 where adventitious roots hreak out from the interior of a stem. 



It is unnecessary to enter into any other points. It is seen that the only matter in 

 which I am agreed with Suminski is the import of the organs and the existence of a sexual 

 conjunction; in all the details of the processes I am at variance with him. Nothing, 

 however, can take from him the credit of having discovered the archegonia and their im- 

 port, one of the most important discoveries in physiological hotany of modern times ; 

 since it has led to results revolutionizing the whole theory of the reproduction of plants, 

 and opened out a totally new sphere of inquiry into the laws and relations of vege- 

 table life. 



The next contribution to the subject to which such a lively interest had been attracted, 

 was a paper by Dr. Wigand *, giving a detailed account of a series of critical observations 

 on the question, and deducing conclusions directly opposed to those of Suminski. Dr. Wi- 

 gand's observations do not seem to have been complete and thorough-going, for he also 

 describes the perfect antheridmm as a single cell, and appears to have confounded the 

 complex structure seen in the effete antheridia with that of the archegonia (p. 23 loc. cit.). 

 His description of the development of the sperm-cells within the antheridia is nearer the 

 truth ; but while right in rejecting the ideas of Nageli and Suminski, that these originate 

 by free cell-formation around a nucleus, he fell into a different error in supposing that the 

 cellules were not in contact at first, but were formed in groups around isolated portions of 

 the cell-contents. His description of the spermatozoids is pretty accurate, but the differ- 

 ences he describes appear to me to indicate different stages of development, and not to 

 depend upon the specific differences of the specimens examined. He overlooked the 

 earliest stages of the growth of the archegoniim, and especially the existence of the 

 embryo-sac beneath the nascent papilla ; the account of the later stages of development 

 of the papilla is tolerably correct. But he observed the later conditions of the abortive 

 embryo-sacs separately, and as independent organs, which he called " peculiar glandular 

 structures " (p. 49 loc. cit.), and he argued directly against their being considered as con- 

 nected with the papilliform structure, closed at its summit, forming the upper free portion 

 of the archegonium. 



Dr. Wigand contends at great length against the existence of a process of impregna- 

 tion, but the only fact of importance I find in his arguments is the statement that he 

 found buds {embryos) in many cases where no archegonium existed on the prothallia. 

 This is contrary to my experience, and I feel confident that his investigations were im- 

 perfect in this respect. Many pages of arguments which he urges against Suminski's 

 views may be passed over, since my own observations, if, as I fully believe them, correct, 

 remove the necessity for discussion, by showing the facts to be different. With regard to 

 Dr. Wigand's arguments against the probabilities of the fertilization, I think it unne- 

 cessary to enter into them, as the analogous conditions since discovered in the allied 

 groups of the Cryptogamia, especially those recently demonstrated to exist in the Lyco- 

 podiacese and Rhizocarpese, turn the balance of probabilities the other way. 



* Zur Entwickelungsgeschichte der Farrenkrauter, von Dr. Albert Wigand. Botanische Zeitung, vol. vii. p. 17 etseq. 

 1849. 



