100 Dr. Griffith on the Formation of 



servable in spiral vegetable fibres, mould, &c, simulating 

 doubly interlacing spirals, are produced by the action of the 

 corrosives employed, as these are not observable without their 

 use ; moreover, it is difficult to imagine that the walls of the 

 cells of the lowest vegetable productions in the scale of or- 

 ganization should be formed of spiral fibres, and a complexity 

 of arrangement which seems almost exclusively to belong to 

 the higher plants ; nor do I believe that nature in her con- 

 stant simplicity would ever make use of so truly artificial an 

 arrangement. A common appearance of double interlacement 

 in muscular fibre results from the apposition of two fibres 

 with oblique striae, as in Mr. Bostock's preparations. As re- 

 gards the existence of primary fibre in vegetables, I think no 

 such productions exist. I am at a loss to conceive how the 

 arrangement of particles about to form a fibre can be produced 

 without their being enclosed within a sac filled with a fluid to 

 allow of free motion of the particles. Were the spiral fibres 

 cells, they might possess the power of growth by elongation, 

 or formation of budding cells, &c. from the extremity of the 

 old ones 5 but this is not the case, they are always solid. More- 

 over Mr. Quekett * has seen and described their mode of for- 

 mation, and I am not aware of, neither do 1 believe in, the ex- 

 istence of any other mode than that described by him. The 

 tissue of Stelis, brought by Meyen from Lucon, in which cells 

 exist apparently formed of fibres only, ought to be referred to 

 that variety described by Slack f where the membrane and fibre 

 have been firmly consolidated. And the fibres on the testa of 

 Collomia I am convinced are surrounded by a true cylindrical 

 membrane with as defined an outline as that of any spiral ves- 

 sel ; the only difference between these fibres and their mem- 

 brane, and those of ordinary spiral vessels is, that in the former 

 the membrane is never in approximation with the fibre, but 

 distended with mucus, and their termination is not in a point 

 as in ordinary spiral vessels ; but the fibre breaks up into di- 

 stinct rings, and I believe they are mere modifications of the 

 spiral vessels similar to those on the testa ofBuellia and Acan- 

 thodium, &c. 



The regularity of the relation of the fibre to the sheath in 

 Cotlomia is much too constant to be regarded as simply mu- 

 cus. In vegetable cells approaching nearest to those described 

 by Meyen where the fibre apparently forms the entire cell, 

 careful examination will nearly always detect evidences of the 

 existence of both fibre and membrane. I think the great 

 cause of " primary vegetable fibre " being found, is the tissue 

 being examined in much too advanced a state. I feel author- 



* Transactions of Microscopical Society, vol. i. 1812. 

 f Transactions of Soc of Arts, vol. xlix. 



