18 CELLULAR TISSUE. 



5 In some cases there are two fibres coiled in oppo- 



site directions. This variety is found in the skin 

 of winged seeds. It constitutes the entire sub- 

 stance of some of the mosses, as the sphagnum. 

 Second ; Fibrous cellular tissue, consists of cells 

 entirely formed of fibre twisted spirally, with no 

 exterior membrane. This curious variety luay be 

 found in the lining of anthers ; also on the sur- 

 face of the seeds of the collomia linearis ; by 

 moistening them, the seed will soon be covered by 

 a coating of the most delicate gauze. This gauze is the fibre 

 Q of the cells uncoiled, (as seen in fig. 6.) This 



form is no doubt of the regular structure, in its 

 earliest stage, but by growth, the membrane is 

 \ torn into threads, corresponding to the internal 

 fibre ; or that the membrane is absorbed in the 

 progress of development. Mirbel found the cells 

 which line the anther of the gourd to be composed of con- 

 tinuous membrane, before the time of flowering. The fibres 

 which form the cells assume a great variety of appearances, 

 when they are broken, after the disappearance of the mem- 

 brane. Lindley has noticed four varieties : 



1. " Short, straight and radiating fibres, so as to form lit- 

 tle star-like appearances, found in the lining of the anthers 

 of the Polygala, by Purkinji. 



2. " Fibres originating in a circle curving upwards into a 

 sort of dome, and uniting at the summit, observed by the same 

 anatomist, in the anthers of the Veronica perfoliata. 



3. " Fibres standing in rows, each distinct from its neigh- 

 bor, and having its point hooked so that the whole has some 

 resemblance to the teeth of curry-comb, in the anthers of the 

 Campanula. 



4. " Fibres forming complete arches, as seen in the anthers 

 of the Linaria cymbalaria." 



13. We have given in the above paragraphs the appearance 

 of those parts of the vegetable tissue which all allow to be 

 of the cellular variety, and although varying so much in ap- 

 pearance, and constitution, yet we believe they all have ori- 

 ginally the same organization. Their development under 

 different circumstances, and the different functions they per- 

 form, have caused their diversity of constitution and appear- 

 ance in a state of maturity. 



14. The cellular tissue has been assigned to the same place 

 in the vegetable economy, that the flesh occupies in the ani- 

 mal, and we have no hesitation in yielding to it in every re- 



