266 Mr. Lindley on Vegetable Tissue. 



mucus, so as to be unable to manifest themselves ; but the 

 instant water is applied, the mucus dissolves, and ceases to 

 counteract the elasticity of the spiral vessels, (spires,) which 

 then dart forward at right angles with the testa, each carrying 

 with it a sheath of mucus, in which it for a long time remains 

 enveloped, as if in a membranous case.' (See Botanical Re- 

 gister, t. 1166.) I, however, fell into the error of considering 

 them spiral vessels ; they are no doubt analogous to those 

 forms of cellular tissue, in which a fibre only is developed, 

 and are probably of the same nature as what Mr. Brown de- 

 scribed, in 1814, as spiral vessels in the testa of Casuarina. 



These cases had clearly demonstrated the coexistence of 

 both membrane and fibre, in the cellular tissue, and also that if 

 the latter is usually found composed of membrane only, without 

 fibre, it is occasionally composed of fibre without membrane. 



Besides these instances, Meyen, about this time, described 

 fibrous cellules in anthers. It was not, however, till last year, 

 that the existence of fibrous cellular tissue was proved to be so 

 extremely common in flowering plants, that scarcely a species can 

 be named in which it does not exist abundantly. It appears from 

 the descriptions of Dr. I. E. Purkinje, (de cellulis antherarum 

 fibrosis, &c.) who, however, does not appear to have been aware 

 of the abovementioned observations, that in anthers, the inner 

 lining of the valves consists exclusively, either of membranous 

 cellules, the sides of which are marked by fibres, arranged either 

 spirally or otherwise, or of fibres only, arising from the cuticle, 

 projecting into the cavity of the anther, and unconnected by 

 any membrane. This statement is illustrated by good figures 

 of nearly three hundred instances, the accuracy of some of 

 which I have so verified, that I feel confidence in that of the 

 remainder. 



It seems probable that this structure, now that attention has 

 been called to it, will be found far from uncommon in the 

 cellular tissue of other parts of plants. I have observed it in 

 the leaves of Brassavola tuberculata in the same state (a very 

 imperfect one) as Dr. Mohl found it, and as I have myself 

 seen it in Rubus odoratus : and it exists in a state of beautiful 

 perfection in the leaves of Oncidium altissimum, where some 

 of the cellules, much larger than the rest, are evidently 



