458 



Transactions. — Geology. 



attention ; but, occurring as they do, it does seem strange how 

 they could have been formed. The only suggestion I can offer 

 to explain this circumstance, is that — having adopted the vol- 

 canic theory in the formation of these downs — immediately 

 after the lava or dolorite beds were spread over the country, the 

 mud and ooze were deposited on them. The great heat of the 

 beds — greatest when thickest — would for a long time keep the 

 mud boiling, and so a quantity of solfataras or mud volcanoes 

 would be formed, and when the whole cooled a shallow basin 

 would be left where they existed. 



