39 



land was continuous from the West of Ireland to the North of 

 Spain, across a large area where now rolls the Atlantic Ocean and 

 the Bay of Biscay, and that the plants of the type known to 

 British botanists as the " Hibernian" type are the remains of an 

 ancient flora that once covered this area now depressed below the 

 sea level. This period of depression, when the land connecting 

 " Old Erin" with the Iberian peninsula was broken up, was 

 also attended by a glacial climate, in which none but sub-alpine 

 or hardy species could exist. Thus Ireland was originally clothed 

 with vegetation of a type different from that which now adorns 

 our country ; and we owe it to the disruption of the land, and the 

 rigorous climate that for a time prevailed, that 'so few species 

 have survived to represent our original flora : that geological 

 agencies have been very efficient in the diffusing or limiting of 

 plants is undeniable : that the geological epoch antecedent to 

 the present was in this country a glacial period is now well estab- 

 lished. To glacial action we owe the main features in the contour 

 of our landscape. That great fluctuations of sea-level have taken 

 place is also past dispute. In our own locality it can be shown 

 that since our valleys were scoped out, since our hills were 

 fashioned into their present shape, the sea — now a thousand feet 

 down below — rolled over the Cave Hill and Black Mountain. It 

 has made its mark, and left its waifs to be seen by any who doubt. 

 Forbes advanced no rash hypothesis. There is sufficient evidence 

 of the geological movements on which he relied, and it may be 

 assumed that they satisfactorily account for the so-called Hiber- 

 nian type of plants found in Galway and the counties adjoining. 



[second paper.] 

 VEGETABLE PARASITES. 



P.Y ME. W. H. FERGUSON. 



Though the general laws which govern the structure and econ- 

 omy of Vegetables be now tolerably understood, there are many 

 deviations from them which offer to the philosophic botanist 

 subjects peculiarly worthy of his study and investigation. Per- 

 haps the most striking exceptions to the prevailing laws are to 



