450 
seen, Dr. Parsons’s judgment was so perplexed; he at first consider- 
ing that to be a petrified fig, which he afterwards concluded to be a 
substance of the fungus kind. The representation at PI. IX. Fig. 3, 4, 
is of a small specimen, being one of those species of this kind of sub- 
stance, which bears a resemblance to a small compressed fig. The 
upper part. Fig. 3, has a gentle rising, as if the stalk had been at- 
tached at that part ; and on the under surface. Fig. 4, is a similar 
depression with that which is borne by the corresponding part of a fig. 
Having been able to mark these substances under many of the va- 
rious shapes they assume, I have no doubt of their being of marine 
origin, and the residence, and perhaps the workmanship, of animals : 
they would not, therefore, have been mentioned in this part of our 
inquiry, but for the sake of showing you that we have now arrived at 
the examination of substances which, though apparently of a vege- 
table, are really of an animal nature ; and that we have therefore 
reached the line at which our present labours should cease. 
Having now furnished you with what information is in my power 
respecting real petrifactions of vegetable substances ; it becomes ne- 
cessary to say a few words respecting those stones which, from their 
accidentally possessing the forms of certain parts of vegetables, have 
been by many supposed to have actually derived their figures from 
the substances which they so much resemble. These stones, the 
Phytogliphi of Wallerius, being a species of the Petrijiciita ficta of 
LinnEeus, Lithoglyphi of Wallerius, and Lapides Jigurati of others, 
have, from their great similitude to different parts of vegetables, 
occasioned numerous mistakes in the writings of the earlier oryc- 
tologists. From circumstances which affect the formation of stones, 
they are more likely to be disposed to assume the oval or globular 
