DR. MARTIN BARRY ON FIBRE. 93 



the existence of filaments, such as those I have described. And here they should be 

 apprized, that the filaments are sometimes exceedingly minute. Such was their condi- 

 tion, for instance, in tendon. In bone also, from which the phosphate of lime had been 

 removed (by muriatic acid), I found them exceedingly minute. The varying appear- 

 ance of the edges of the filament, just referred to, may assist to explain why some 

 have believed " fibre" to consist of globules ; while others have maintained that no 

 globules can be discerned in it. 



The Spiral Form as general in Animals as in Plants Universality and Early 



Appearance of the Spiral Form. 



1 7. It is known that vegetable tissue presents, in some parts, a feature which has 

 heretofore seemed wanting, or nearly so, in that of animals the spiral form. I 

 venture to believe that some appearances met with in my investigations may go far 

 towards supplying this deficiency. These appearances will be found represented in 

 the nervous tissue (Plates VI., VIII., IX.), in muscle (Plates VI., VII., VIII., IX.), in 

 minute blood-vessels (fig. 16), and in the crystalline lens (fig. 131). If indeed the 

 view above mentioned that the larger and the smaller filaments have the same 

 structure be correct, it follows that spirals are much more general in plants them- 

 selves than has been hitherto supposed. Spirals would thus appear, in fact, to be 

 as universal as a "fibrous" structure. 



18. The tendency to the spiral form manifests itself very early. Of this the most 

 important instance is afforded by the corpuscle of the blood, as above described. I 

 have also obtained an interesting proof of it in cartilage from the ear of a rabbit 

 (figs. 133 to 136), where the nucleus, lying loose in its cell, resembled a ball of 

 twine ; being actually composed, at its outer part, like the nuclei of certain blood- 

 corpuscles, of a coiled filament ; which it was giving off to weave the cell-wall ; 

 this cell-wall being no other than the last formed portion of what is termed the inter- 

 cellular substance the essential part of cartilage. 



19. I think there is ground for believing, that the nucleus of the cell in cartilage, 

 now compared to a ball of twine, is descended by fissiparous generation from the 

 nucleus of the blood-corpuscle; which on a former occasion-)- we saw to give the 

 first origin to cartilage, for I have never seen the nucleus of a cell arise, except as 

 part of a previously existing nucleus^. It is therefore interesting now to find in 

 each the appearance which I have compared to a ball of twine: though it is not 

 likely that cartilage is the only tissue to which the blood-corpuscle transmits the 

 property in question. 



Mode of Origin of the Flat Filament (" Fibre") Its Reproduction. 



20. It is known that, in order to the formation of certain fibrous tissues, cells 



t Philosophical Transactions, 1841, PI. XXII. figs. 116^ 122. 



\ Some of the nuclei in the cells of cartilage in figs. 134, 135, were apparently undergoing division. 



