Prof. LiNDLEY on the Anatomy of the Roots o/Ophrydeee. 427 



It then appeared that the nodules, apparently so homogeneous, are composed 

 of extremely minute transparent cells, filled, I presume, with a secretion of 

 the same refractive power as themselves, and adhering to each other so firmly, 

 that in their fresh state no spaces could be detected among them. In their 

 charred condition, however, the double walls of the cells, intercellular si)aces, 

 and even here and there the cytoblasts, became so distinctly visible, that the 

 accompanying figure 3. was readily made with a camera lucida adapted to an 

 achromatic microscope magnifying 480 diameters. 



These statements are, I should think, sufficient to show that the roots of 

 Ophrifdece are not composed, to any great extent, of starch, but that their 

 peculiar properties are owing to the presence of a large quantity of a gummy 

 secretion, which for the present may be called Bassorine, collected in cellular 

 horny nodules. 



It remains for me to explain in what way the error has probably arisen of 

 those who, like Guibourt and Payen, describe Salep as chiefly composed of 

 starch. It is well known that Salep is prepared by boiling the roots of Ophry- 

 dece, and then drying them. The effect of boiling is to dissolve what starch 

 exists in the parenchyma surrounding the nodules of Bassorine ; the dissolved 

 starch will flow over the sides of the cells and the surface of the nodules, 

 from which when dried it becomes undistinguishable ; and consequently when 

 iodine is applied to Salep, the whole mass will appear to have become iodide 

 of starch. Attention having been called to the facts above mentioned, there 

 remains no difficulty in seeing that the general diffusion of blue is apparent 

 only. In reality, if, after iodine is applied to Salep and the blue colour is pro- 

 duced, the nodules are removed, which is not difficult, they are found to re- 

 tain their original vitreous lustre, and to have been coloured apparently only 

 by the reflection, through their semitransparent sides, of the blue iodide of 

 starch by which they are surrounded. That this explanation is true, may be 

 proved experimentally, by examining the roots of Orchis maculata, both fresh 

 and subsequently to their being made into Salep. 



February 2, 1839. 



