36 Mr. BakewelloM the progressive Development of Organic Life. 



A living lizard was found in a bed of coal at Rothwell Haigh 

 near Leeds, about twelve years since. I saw it soon after it was 

 found, preserved in spirits: it was nearly seven inches long, 

 and is now in the possession of the Rev. Dr. Sharp, vicar of 

 Wakefield. The depth of the mine is one hundred and eighty 

 yards ; it has been worked many years ; and being situated in 

 elevated ground, has levels for drainage nearly as low as the 

 river Calder, so that it is not very difficult to admit that the 

 lizard might find a ready passage into the mine, and have 

 sunk into a fissure in the coal, and remained there in a nearly 

 torpid state till it was discovered in working the coal. Had 

 the lizard died, and its bones become mineralized by water con- 

 taining the sulphate and carbonate of iron, which abounds in 

 the mine, we should have had an instance of a saurian animal 

 in coal, which might have been cited to prove the high anti- 

 quity of a species of reptile similar to what is now living in 

 the country. The experiments of the late Dr. Jenner, which 

 I have mentioned elsewhere, prove that bones may be par- 

 tially mineralized in a few months by immersion in lias mud, 

 containing much metallic and saline matter. On the other 

 interesting disquisitions in Mr. LyelPs work, it is not my in- 

 tention to offer any remarks at this time ; they cannot fail to 

 render an important service to geology, by the searching in- 

 vestigations to which they will undoubtedly give rise : but I 

 maintain that the theory of the progressive development of 

 organic life cannot be overturned by individual anomalous 

 exceptions, by ingenious reasoning, or by negative evidence*. 

 It is true that this theory, which holds that a succession of 

 more perfect classes and orders of animals may be traced, 

 in ascending from the lower or more ancient strata, to the 

 more recent formations, has been carried too far by some of 

 its supporters; and like other general conclusions in every 

 science, requires to be admitted with certain limitations : yet 

 it appears to me, in the present state of our knowledge, to 

 be one of the most interesting and best established doc- 

 trines in geology. Whenever several individuals belonging 

 to different genera, in any of the higher orders of the class 

 Mammalia, shall be discovered in the ancient strata, then in- 

 deed may we fairly admit that the theory of the progressive 

 development of organic life is completely refuted. 



I had intended to send some observations on certain parts 

 of the geology of Nottinghamshire, Derbyshire, and Leicester- 



By negative evidence, is meant that which is grounded on our igno- 

 rance of the organic remains that may possibly exist in the ancient strata, 

 in countries that have not yet been examined. 



shire, 



