APPENDIX. 905 



masses, which by the further operation of air and moisture, gradually 

 lose their solid angles, and approach the spheroidal form. The fact 

 of the upper part of the cliff being more exposed to atmospheric 

 agency than the parts beneath, will sufficiently explain why these 

 rounded masses so frequently rest on blocks which still preserve the 

 tabular form ; and since such spheroidal blocks must obviously rest in 

 that position in which their lesser axes are perpendicular to the 

 horizon, it is equally evident that, whenever an adequate force is 

 applied, they must vibrate on their point of support." — Philosophy in 

 Sport, sixth edition, p. ±Q5. 



C. Page 874.— The Rev. J. B. Reade, F.R.S. &c. on Fossil Inftt- 

 BQ&ia ; in a letter to the Author. — " You are aware that a micro- 

 scopic examination of recent and fossil plants has not only enabled me 

 to establish some important facts in vegetable physiology, but has 

 also led me to pursue an investigation intimately connected with 

 1 the Wonders of Geology.' With respect to plants, I have already 

 shown that the solid materials which are contained in their ashes, 

 must be ranked amongst their essential elements ; and that while the 

 carbon may be readily dissipated by heat, their solid and earthy 

 ingredients, whether silica or lime, so perfectly retain the form and 

 characters of the cells and tubes into which they enter, that the burnt 

 and unburnt specimens have sometimes been mistaken, the one for 

 the other (seep. 711). I premise this remark, because it enables me 

 to reply to your query, respecting the possibility of the existence of 



Lign. 198. — Flat circular bodies in mica schist. 



Corresponding in size and appearance with the rings of Gaillonella distans; 

 magnified about 500 times linear. 



(By the Rev. J. B. Reade.) 



organic structure in granite, by observing, in the first place, that 

 much of what I have stated with regard to plants, is equally applica- 

 ble to large portions of the animal kingdom also, and especially to 

 that section of it, viz. the Infusoria, which might appear, at first sight, 

 to be wholly removed from such speculations. 



" My original inquiry having thus conducted me to the conclusion, 

 that siliceous organization is not destructible by the agency of heat. T 

 thought it not unreasonable to infer that a careful and more extended 



