Prof. A. Henfrey on Cell-development in Plants. 417 



XL, — On Ci'll-dcvclopment in Plants. 

 By Prof. Arthur Hknfrev, F.R.S. 



Tu the Editors of the Annals of Natural History. 

 Gentlemen, April 18, 185fi. 



In a recent Part of the * Transactions of the Microscopical 

 Society of London ' appeared a paper entitled "On the Formation 

 and Development of the \'cgetable Ccll/^ by Mr. Wenham 

 (Quarterly Journal of JMieroscopic Science, January 185G), a 

 well-known mieroscopist. This essay, containing internal evi- 

 dence of the author's want of familiarity with the subject treated, 

 tended to revive the long-exploded hypothesis that vegetable 

 cells originate as bubbles or vacuoles in a formless 'plasma,' 

 into which cavities the true cell-contents penetrate after the 

 formation of the cell. The paper would not have required any 

 notice at the hands of physiological botanists, had it not been 

 endorsed in some degree by the late President of the Microscopic 

 Society in his Anniversary Address (Quarterly Journal, April 

 1856). The deservedly high authority of Dr. Carpenter as a 

 physiologist renders it necessary that a protest should be entei-cd 

 by some one having practical experience in these matters. I 

 have no hesitation in saying that Mr. Wenham's observations 

 are faultj^, consequently his conclusions useless. The objects 

 selected for observation were unfavourable, and not favourable as 

 he imagined; for young leaves of most tiowering plants, in the 

 stages tigured by him, are not flat plates, but cones, or at all 

 events solids having more than one thickness of cells in all three 

 dimensions ; therefore the view is confused by one layer lying 

 behind another. The young leaves of most Mosses or Liver- 

 worts, the prothallia of Ferns, and similar structures composed 

 of a single flat layer of cells, exhibit the phsenomeua much more 

 clearly ; but even in the young leaves of Anacharis, the applica- 

 tion of dilute sulphuric acid and solution of iodine suffices to 

 render the structures clearly distinguishable as quite different 

 from what is represented in Mr. Wenham's drawings. The 

 appearances presented by the protoplasmic structures in such 

 nascent tissue are familiar to most of those who have practically 

 studied these questions, so that it is merely necessary for me to 

 state, from my own experience, that the objects observed by 

 Mr. Wenham really offer no exception to the general rule, that 

 the primary cell- wall is formed on the outside of the mass of 

 protoplasm {primordial utricle, protoplast, primordial cell, por- 

 tion of cell-contents, or whatever we may choose to call it), which 

 is to form the active nitrogenous contents of the future cell. 



I am, &c., yours truly, 



Arthur Henfrey. 

 Ann. ^ Mag. N. Hist. Ser. 2. Vol. xvii. 27 



