172 ON BIO-GEOLOGY. [vn. 



colonies, on the spots nearest the coast which were fit 

 for them. 



I trust that I have not kept you too long over these 

 details. What I wish to impress upon you is that 

 Hampshire is a country specially fitted for the study of 

 important bio-geological questions. 



To work them out, you must trace the geology of 

 Hampshire, and indeed, of East Dorset. You must try 

 to form a conception of how the land was shaped in 

 miocene times, before that tremendous upheaval which 

 reared the chalk cliffs at Freshwater upright, lifting 

 the tertiary beds upon their northern slopes. You 

 must ask Was there not land to the south of the Isle 

 of Wight in those ages, and for ages after ; and what 

 was its extent and shape ? You must ask When was 

 the gap between the Isle of Wight and the Isle of Pur- 

 beck sawn through, leaving the Needles as remnants 

 on one side, and Old Harry on the opposite ? And was 

 it sawn asunder merely by the age-long gnawing of 

 the waves ? You must ask Where did the great river 

 which ran from the west, where Poole Harbour is 

 now, and probably through what is now the Solent, 

 depositing brackish water-beds right and left where, 

 I say, did it run into the sea ? Where the Straits of 

 Dover are now ? Or, if not there, where ? What, too, 

 is become of the land to the Westward, composed of 

 ancient metamorphic rocks, out of which it ran, and 

 deposited on what are now the Haggerstone Moors of 

 Poole, vast beds of grit ? What was the climate on its 

 banks when it washed down the delicate leaves of broad- 

 leaved trees, akin to our modern English ones, which are 

 found in the fine mud-sand strata of Bournemouth ? 

 When, finally, did it dwindle down to the brook which 



