506 Dr. W. B. Carpenter on Vegetable Cell- formation. 



no ground for charging me with adopting his corrections without 

 acknowledgment, will appear from the following quotation from 

 the article " Shell," which I contributed to the ^ Cyclopsedia of 

 Anatomy and Physiology' (vol. iv. pp. 563, 564); — '^ When 

 thin sections are microscopically examined, they present a very 

 peculiar texture (shown in the figure), which might be referred 

 either to long flattened cells, or to plications in the shell-mem- 

 brane The cells, if cells they be, must be excessively 



flattened, and no vestige of them can be traced in the decalcified 

 shell ; whilst, on the other hand, the membranous residuum does 

 not give any distinct indication of having been plicated with the 

 regularity necessary to produce such a remarkable appearance," 

 Now this passage was written in 1848 or early in 1849, conse- 

 quently long before the publication of Prof. King's Monograph. 



I must trespass a little further upon your space, for the 

 purpose of requesting your readers to suspend their judgment 

 upon the question on which Prof. Henfrey has pronounced (in 

 your last Number, p. 417) a very positive opinion in opposition to 

 mine, — namely, the value to be attached to Mr. Wenham's ob- 

 servations on the process of cell-development in plants. No one 

 has a higher estimate than myself of Prof. Henfrey's acquire- 

 ments in vegetable physiology; but since I happen to know 

 that Mr. Wenham's conclusions are borne out, as to certain 

 important particulars, by the testimony of other independent 

 observers, who will probably ere long make public the facts 

 they have witnessed, I venture to believe it possible that Prof. 

 Henfrey may be mistaken. What I considered to be the essen- 

 tial point in Mr. Wenham's observations was this, — that a mass 

 of protoplasm may resolve itself into cells by a process of vacuo- 

 lation in the parts which are to be the cell-cavities, and of con- 

 solidation in those which are to become the cell- walls, essentially 

 corresponding with that which takes place in the development 

 of a single cell from a " gonidium " or any other isolated particle 

 of protoplasm. That this doctrine does not agree with Prof. 

 Henfrey's general ideas of the process of cell-formation, is no 

 more proof that it is wrong, than the denial of the sexual nature 

 of the antherozoids of Cryptogamia by Prof. Schleiden proved 

 that doctrine to be invalid. When Mr. Wenham's observations 

 shall have been shown to be incorrect as to the essential point just 

 mentioned^ I shall be quite ready to retract the " endorsement " 

 which I gave to them. 



I am, Gentlemen, 



Yours sincerely, 



William B. Carpenter. 



