6 
INTEODUCTION. 
only because he adds Abingdon Island to the list of those in which Tortoises occur 
('Voyage to the South Atlantic,' Lond. 1798, 4to, p. 152). Also Capt. Basil Hall 
landed on this island in 1822, where he found plenty of large Tortoises, of which he 
laid in a stock which lasted the ship's company for many weeks (' Extracts from a 
Journal,' Edinb. 1824, 8vo, 2nd edit. vol. ii. p. 140). 
Twenty-two years had passed since Porter's cruise when Darwin visited the Galapa- 
gos in the ' Beagle ' in the year 1835. A change, by which the existence of these 
animals was much more threatened than by the casual visits of buccaneers and whalers, 
had taken place. The Republic of the Equator had taken possession of the archipelago; 
and a colony of between two and three hundred people banished by the Government 
had been established on Charles Island, who reduced the number of Tortoises in this 
island so much that they sent parties to other islands (for instance James) to catch Tor- 
toises and salt their meat ('Journal,' pp. 375, 376). Pigs had multiplied, and were 
roaming about the woods in a feral state. Darwin adds many interesting observations 
on the habits of these Tortoises ; but as his ' Journal ' is in everybody's hands, I quote 
from his account such parts only as have a special bearing on questions with which we 
shall have to deal in this treatise. He confirms Porter's observation as regards their 
deafness, also that " the old males are the largest, the females rarely growing to so great 
a size. The male can readily be distinguished from the female by the greater length of 
its tail " (p. 382). An egg which he measured was 7f inches in circumference, a 
measure nearly identical with that found by Porter. " The old ones seem generally to 
die from accidents, as from falling down precipices ; at least, several of the inhabitants 
told me they had never found one dead without some evident cause " (p. 384). " The 
Vice-Governor, Mr. Lawson, declared that the Tortoises differed from the different 
islands, and that he could with certainty tell from which island any one was brought. 
. . . M. Bibron, moreover, informs me that he has seen what he considers two dis- 
tinct species of Tortoise from the Galapagos, but he does not know from which islands. 
The specimens that I brought from three islands were young ones, and, probably owing 
to this cause, neither Mr. Gray nor myself could find in them any specific differences ' 
(p. 394). 
After an interval of not quite eleven years, H.M.S. ' Herald ' followed the ' Beagle ' 
on a voyage of discovery and survey. The naturalist of that expedition, which reached 
the Galapagos in the year 1846, found that the progress of civilization had been great 
('Narrative of H.M.S. Herald,' by B. Seemann: Lond. 1853, 8vo), or, in other words, 
that the displacement of the indigenous fauna by man and his companions had pro- 
ceeded apace. On Charles Island "the cattle had increased wonderfully, and were 
estimated at 2000 head, beside wild pigs, goats, and dogs. . . . The wild dogs keep 
the goats and pigs very much down" (vol. i. p. 57) ; but " no turpin, or terrapin, are 
living on this island " (p. 59) ; that is, the Tortoises had been exterminated between 
the visits of the ' Beagle ' and the ' Herald.' On Chatham Island " we saw, for the 
