811 



after a brief interval, the utricle becoming either almost destroyed or 

 a mere thread lying in the cells. 



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

 fibrous deposit connected with the irregularly-distributed covexilies 

 of the cell-wall, and which gives rise to the frequently somewhat sinu- 

 ous outline of the hair ; but T 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 inva- 

 riably present more or less the appearance of dots, or rather slits, 

 generally in a direction somewhat parallel with the axis of the hair, 

 but sometimes also slightly inclined in a spiral (as in the unicellular 

 hairs of the corolla), ascending to the right, as viewed from the cen- 

 tre. The edge of the lower portion of these hairs sometimes presents 

 an almost even outline ; but frequently (and perhaps nearly always 

 toward the extremity of the hair) a slight, irregular beading occurs, 

 exactly as we might expect were the dots or markings occasioned 

 by external matter ; but I am not sure that this appearance is in- 

 compatible with the idea that they may be openings, or slits, in a 

 secondary deposit on the common wall of the hair, which, from an 

 examination solely of the markings in the central portions, we might 

 conclude they were. I have not detected, in these hairs, actual mo- 

 tion of the cell-sap ; but mucilaginous threads may be easily seen, 

 radiating irregularly from the nuclear vesicle, indicating such a circu- 

 lation. With regard to the contents of the nucleus, I cannot certainly 

 speak. Sulphuric acid, diluted, causes the primordial utricle to con- 

 tract, and lie in the interior, as a loose sac. In some small cells, the 

 separation is not apparent after twenty-four hour's action. 



" A solution of chloride of calcium causes a partial dissolution of 

 the primordial utricle, certain bodies, perhaps including the true 

 nucleus, remaining visible. 



