426 Prof. LiNDLEY on the Anatomy of the Roots q/" Ophrydeae. 



The roots of all the other Ophrydece, whether European or not, which I 

 have had the opportunity of examining, are constructed essentially in the same 

 manner as that of Satyrium pallidum. The differences I find among them 

 consist chiefly in the size and shape of the nodules, and in the proportion they 

 bear to the surrounding parenchyma ; in the quantity of starch formed in the 

 latter ; and in the way in which sections of the tubercles are affected by expo- 

 sure to the air. In Orchis maculata, for instance, there is more starch than 

 usual, the nodules when fresh are not much larger than the cells of surround- 

 ing parenchyma, and the section of the root remains white, while in Satyrium 

 pallidum it becomes deep brown. Beyond this I have observed nothing which 

 deserves notice. 



But while the presence of nodules is so universal in this tribe of Orchi- 

 daceve, it is not a little singular that they should be as generally absent in 

 the tubercles of the other tribes of the same natural order. Up to the present 

 time I have not succeeded in detecting them in any species of Neottiece or 

 Arethusece, of which I possess roots. In the tubercles of New Holland Orchi- 

 dacece the cells appear to be exclusively occupied by starch, with which they 

 are in fact filled ; at least, such is the case in Glossodia minor, Thelymitra 

 carnea, and another species, Caladenia testacea, Corysanthes bicalcarata, and 

 many species of Diuris and Pterostylis. 



I have already stated that the nodules appear to be homogeneous. But the 

 slowness with which their horny contents are acted upon by the alcoholic so- 

 lution of iodine, and the frequent arrangement of the secretions of plants in a 

 stratified manner in the lignified parts of vegetation, led me to suspect that 

 this homogeneity was only apparent. Nevertheless, for a long time I sought 

 in vain for evidence of their contents being organized ; in whatever way they 

 were cut, whatever reagents were employed, sections of the nodules presented 

 the same unvarying uniform surface. At last, upon examining some Covent 

 Garden Salep, — a coarse preparation of wild Ophrydece, — thin slices of which 

 I had made with a knife whose edge had lost its keenness, and which therefore 

 bruised the Salep while cutting it, an indistinct granular appearance became 

 visible upon some of the divided nodules, not however so well defined as to 

 enable me to judge of its real nature. But upon charring the slices by 

 Mr. Reades' process, a beautiful definition of the granulation was obtained. 



