83 



land, which may be compared to Ireland and Scotland in di- 

 mensions, appear to possess no indigenous quadrupeds except 

 the bat ; and this becomes the more striking when we recollect 

 that the northern extremity of New Zealand stretches to latitude 

 34°, where the warmth of the climate must greatly favour the 

 prolific development of organic life *." 



Australia is exceedingly deficient in Saurians and other ter- 

 restrial quadrupeds. Hence the contents of the carboniferous 

 group accord well with the prevalence of such a state of things in 

 the southern hemisphere during their respective depositions. 



We cannot expect to find any large coal formation south of 

 the tropics, but mere beds of lignites ; because should there be 

 any forming it would be below the level of the sea, and not yet 

 sufficiently consolidated to make good coal. The coal forma- 

 tion of Australia is a similar new formation. " In the inlet of 

 Awaaba, in 33° south latitude, is a formation of conglomerate 

 and sandstone, with subordinate beds of lignite, which extends 

 from the Hunter river southwards towards Brisbane water. The 

 lignite constitutes the so-called Australian coal f" 



Tree ferns, which require abundance of moisture and an equa- 

 lization of the seasons, are found in Van Diemen's Land in south 

 latitude 42°, and in New Zealand in south latitude 45°. The 

 orchideous parasites also advance to the 42° south latitude. 



Before concluding this part of our inquiry, we shall make a 

 few observations on the supposed predominance of carbonic 

 acid in the atmosphere during the deposition of the coal-beds. 

 The researches of M. A. Brongniart on fossil plants led him to 

 conclude that during the early period, when the plants entombed 

 in the coal-measures of the northern hemisphere flourished, the 

 atmosphere was more charged with carbonic acid than at pre- 

 sent, aiding, it is said, the development of the gigantic species 

 seen in the coal, and also protecting them when dead from being 

 so readily decomposed by the atmosphere. 



It is difficult to conceive how the idea of plants obtaining 

 their carbon from the atmosphere originated, when it is a well- 

 known fact that it is obtained from the soil. No such atmo- 

 sphere exists in the southern hemisphere, nor within the tropics, 



* Lyell, Principles of Geology, vol. i. p. 199. 

 t Geological Proceedings, March 8th, 1843. 



G 2 



