76 Botanical Society of Edinburgh. 



or 300 diameters, discovers the appearance of a narrow fibre winding, 

 in a spiral direction, up the inner wall of the cell, ascending to the 

 right (as seen from its axis), and closely applied to the apparent 

 outer cell-membrane, which has become in part absorbed. Numerous 

 elongated and narrow slits or line-like markings occur throughout 

 the spiral, but whether they are openings between the edges of an 

 individual thread, or series of fibres, or analogous to the dots and slits 

 of ])roken vascular tissue, it is not very easy to pronounce. 



When examined iia fluid, this fibrous deposit has the appearance 

 either of a coil of irregular breadth, or of a plexus or branching 

 arrangement of fibre, between the threads of which a line of chvision 

 is perceptible ; if a dried hair be placed under the microscope, we 

 only see slits, narrow and rounded at the extremities, in the direction 

 of the spiral ascent ; these are probably an altered condition of the 

 exceedingly fine separating lines, discovered in the fresh state. The 

 portions of fibrous matter intervening between these openings are of 

 very irregular breadth. The threads of the fibre vary from the 

 1-GOOOth to 1 -9000th of an inch in breadth. After observation with 

 my highest magnifying power, one of Powell and Lealand's excellent 

 :f-inch objectives, I am not prepared certainly to describe the true 

 condition aud arrangement of tliis secondary spiral deposit. 



In a hair of the young corolla (the latter about the 1-Gth of an 

 inch in length), I observed the spiral arrangement pretty distinctly ; 

 in the younger stages the cuticle does not appear to have become 

 absorbed to such an extent as in the matured cell, a double wall 

 being perceptible towards the extremity of the hair. 



The primordial utricle is readily separated from the cell-wall by 

 the application of reagents. A solution of chloride of calcium pro- 

 duces this effect after a brief interval, the utricle becoming either 

 almost destroyed, or a mere thread lying in the cell. 



I have thought that I may have observed an alteration in the fibrous 

 deposit, comiected with the irregularly distributed convexities of the 

 cell-wall, and which gives rise to the frequently somewhat sinuous out- 

 line of the hair, but I cannot certainly mention an instance. The 

 spiral fibre, if such it be, is quite incapable of unrolling, at least in 

 the cases which I have examined, and the wall of the hair tears in a 

 manner almost totally irrespective of its direction. 



Series of spiral vessels, sometimes branching, are met with in the 

 corolla, but I do not discover any direct communication between these 

 vessels and the spiral cells. 



I have not detected any movement of the cell-sap in this tissue ; 

 merely at times a slight molecular motion. 



With regard to the multicellular hairs, these are readily obtained 

 from any portion of the young exposed plant, but the curious filiform 

 processes from the petiolary sheath furnish them without trouble 

 in a condition easily prepared for examination. 



The hairs consist of a variable number of cells, sometimes as many as 

 nineteen, applied by their extremities. They almost invariably present 

 more or less the appearance of dots, or rather slits, generally in a direc- 

 tion somewhat parallel with the axis of the hair, but sometimes also 



