562 Dr. Michael Grabham [May 5, 



shells which are common to the islands and the mainland, for there 

 has been here free access in past times. 



We depend likewise on the evidence of shells and corals for our 

 knowledge of the period during which the islands of the Madeira 

 province were built up, deposits of these, once at the sea level and 

 now high above the ocean, showing an Upper Miocene association. 

 It is probable, however, that these mountain tops lifted their heads 

 above the water in ages long anterior to the raising of the shelly 

 beds from the seashore to their present altitudes of about 1,500 feet, 

 and that the immense piling up of volcanic ejecta to form these 

 islands 6,000 feet high in countless reiteration of eruption and 

 lengthy periods of repose, began at least long before these fossils 

 were living creatures on the Miocene shore. 



The time taken in moulding the Madeiras to their present form 

 we can only guess at. 



The agencies of transport and distribution we know ; the sea 

 currents are the same ; the same winds prevail ; and birds, both 

 migrants and stragglers, all potential carriers, still come and go — 

 though it may be hard to imagine that these stupendous gorges have 

 been carved out of the volcanic material by the busy little stream 

 below leaping from rock to rock, or that the plants which clothe 

 their mountain sides and represent in their variety almost all the 

 known natural orders ; that the Testacea already spoken of should 

 have been established in 170 well-defined species ; that nearly 700 

 species of the Coleoptera have been described, and that the presence 

 of all these has been due to fitful and accidental influence, working 

 sparingly now as formerly to bring so many forms of life to a group 

 of completely isolated rocks in mid-ocean. 



The forces of disintegration and erosion are equally difficult to 

 fathom. In these regions there are no frosts or temperature ex- 

 cesses to disturb the placid flow of time or accelerate change, and 

 thus after sixty years of familiar acquaintance with Madeira, it would 

 be hard for me to point to a single rock or ravine as having appre- 

 ciably lessened or deepened, though the rain of every winter carries 

 away thousands of tons of material to the ocean and substantially 

 wears away the land. 



The archipelago came to us 500 years ago, so to speak, ready 

 made, with every feature of its structure already well worn and with 

 every species both of flora and fauna already specialized and estab- 

 lished ; and though the historical period of observation has been too 

 short to show any definite variations in either indigenous or natura- 

 lized species, changes from ancestral forms are clearly indicated in 

 the surviving fossils and semi-fossilized Testacea of the rocks. 



The discovery of the Madeiras was due to the accident of a crazy 

 vessel of Prince Henry the Navigator drifting from its course to 

 West Africa during a severe storm in the year 1419. This Henry 

 is the famous Portuguese prince to whom so much of the early 



