THE CELL-THEORY 



259 



or " nucleus," as indicating its homology with the structure of that 

 name, in the plant. 



The primordial utricle was, as we have said, not then discovered in 

 the latter, and of course Schwann was not led to look for anything 

 corresponding to it. Indeed, had he done so, his search would have 

 been unsuccessful, for the young and unaltered cartilage cavity contains 

 the corpuscle, and nothing else. The circumstance, therefore, which 

 Schwann considered to demonstrate the identity of structure of plants 

 and animals — i.e., the correspondence of 

 the cartilage-corpuscle with the nucleus of 

 the vegetable-cell, and of the chondrin-wall 

 with the cellulose-wall, would, if it were 

 really the case, be the widest possible 

 ground of distinction between the two, for 

 it would leave the most important element 

 of the latter, the " primordial utricle," with- 

 out any homologue in the animal, and 

 totally unaccounted for. 



It is precisely the neglect of this im- 

 portant change in the whole subject, 

 effected by the discovery of Von Mohl, 

 which has, we think, led to the confusion 

 which prevails at present, not only in the 

 ■comparative, but in the absolute nomen- 

 clature of animal histology. Animal 

 physiologists go on using Schwann's 

 nomenclature, forgetting that the whole 

 doctrine of the vegetable-cell, from which 

 he drew that nomenclature, has been com- 

 pletely up.set ; and at present, beyond the 

 mere fact of a common vesicularity at one 

 period of their existence, one would be 

 led, on opening successively two works on 



animal and vegetable structure, rather to predicate their total 

 discrepancy, than any uniformity between them. 



Now does this discrepancy lie in the facts, or in our names of them ? 

 To decide this question, it seemed to us that the only plan was to 

 follow Schwann's steps, and to compare cartilage with a vegetable 

 tissue — for he has shown logically and conclusively enough, that 

 whatever is true of the corpuscle of cartilage, to which he gives the 

 name of " nucleus," is true also of all those corpuscles in the other 

 tissues, to which he gives the same name. 



S 2 



Fig. I. 



A, CoUenchyma cells of Beta 

 vulgaris ; B, Stellate tissue of 

 the pith of the rush ; C, a 

 cartilage-cell with its corpus- 

 cle, to compare with D, a 

 vegetable-cell with its nucleus, 

 the primordial utricle in the 

 latter being indicated only by 

 a dotted line. 



