THE BOUNDARY-LINE BETWEEN GEOLOGY AND HISTOKY. 229 



information on the order of their appearance also belongs to Edward 

 Forbes. 



The gradual appearance of these species is connected with the estab- 

 lishment of a milder climate, a consequence of the great depression or 

 sinking of the European coasts, through which the sea gradually en- 

 croached on the Rhine, forming the North Sea and also St. George's 

 Channel. With the immigration of new species the British Islands 

 gradually separated from the continent, and this isolation had been 

 already accomplished before the new comers had spread. These found 

 insuperable obstacles in the newly formed channels, and never reached 

 Great Britain. Hence it comes that of the twenty-two species of rep- 

 tiles existing in Belgium, only eleven are found in England, and only 

 five in Ireland. 



According to Mr. Thompson, if we compare the Irish fauna with the 

 English, we will find that tha former is deficient in many instances. 

 Ireland lacks fourteen or lifteeu species of the eighteen English varie- 

 ties of bats, many other common animals, as the squirrel, the dormouse, 

 all field-mice without exception, the common field-hare, the pole-cat, 

 the wild cat, the mole, many kinds of shrew-mice, all snakes, the common 

 lizard, {Lacerta agilis,) &c. All these, we may therefore suppose, reached 

 England only after Ireland had separated. Hence we see why the 

 mountain-hare is found on the Irish mountains, while the common field- 

 hare is wanting in the valleys. It also appears that some of the most 

 common inhabitants of our fields and meadows are among the animals 

 wanting in Ireland. Perhaps the country was composed only of forests 

 and swamps at the time Ireland became separate. 



We furthermore see that the animals now existing together in Cen- 

 tral Europe did not appear together ; they may, therefore, be divided 

 into groups, not according to their organization as by the systematist, 

 but simply according to the date of their appearance in Central Europe. 



It is from this point of view that we may obtain the means of judging 

 of the first appearance of man in these regions. We must show under 

 what circumstances the most ancient traces of man were found. Two 

 instructive and fully accredited discoveries will suffice to show that the 

 first appearance of man dates much farther back than is generally sup- 

 posed. 



1. Belgian scholars (especially Schmerling and Spring) found humai.i 

 bones and crudely made weapons of flint in the caverns of Gouffon- 

 taine and Chokier in the " Trou chauvan" between Namur and Dijon. 

 These remains were accompanied by the bones of the cave-bear, hyena, 

 lion, " schelch" deer, and a species of horse, in a manner which leaves 

 no doubt as to their co-existence. Three fragments of human skulls 

 were found there, which differ from all at present existing in Europe by 

 being long and flattened out at the sides and by the shape of the fore- 

 head. They apparently belonged to an elderly man, a twelve-year-old 

 and a seven-year-old child. Human lower jaws have also been found. 



