vii.] BEFORE THE STRAITS. OF DOVER. 169 



I spoke just now of the time when England was 

 joined to France, as bearing on Hampshire botany. It 

 bears no less on Hampshire zoology. In insects, for 

 instance, the presence of the purple emperor and the 

 white admiral in our Hampshire woods, as well as the 

 abundance of the great stag-beetle, point to a time 

 when the two countries were joined, at least as far 

 west as Hampshire; while the absence of these insects 

 farther to the westward shows that the countries, if 

 ever joined, were already parted; and that those 

 insects have not yet had time to spread westward. 

 The presence of these two butterflies, and partly of 

 the stag-beetle, along the south-east coast of England 

 as far as the primeval forests of South Lincolnshire, 

 points, as do a hundred other facts, to a time when 

 the Straits of Dover either did not exist, or were the 

 bed of a river running from the west ; and when, as I 

 told you just now, all the rivers which now run into 

 the German Ocean, from the Humber on the west to 

 the Elbe on the east, discharged themselves into the 

 sea between Scotland and Norway, after wandering 

 through a vast lowland, covered with countless herds 

 of mammoth, rhinoceros, gigantic ox, and other 

 mammals now extinct; while the birds, as far as 

 we know, the insects, the fresh-water fish, and even, 

 as my friend Mr. Brady has proved, the Entomostraca 

 of the rivers, were the same in what is now Holland as 

 in what is now our Eastern counties. I could dwell 

 long on this matter. I could talk long about how 

 certain species of Lepidoptera moths and butterflies 

 like Papilio Machaon and P. Fodalirius, swarm 

 through France, reach up to the British Channel, and 

 have not crossed it, with the exception of one colony 



