164 NEW YORK ZOOLOGICAL SOCIETY. 
and saw another tortoise lying in a hollow filled with water. He 
remained there all night apparently, for on our return the next 
morning he was still in it. These two observations rather tended 
to disprove my theory regarding one of the causes of the annual 
migration which affects nearly all the species of Galapagos tor- 
toises. I had formed the opinion that the migration was partly 
due to the slightly colder weather and heavy rains high up on 
the mountains during the winter season, but it would seem from 
the actions here cited that these causes have but little to do with 
it after all. With this species (Testudo vicina), it might be the 
mating instinct that causes them to wander down three or four 
miles from their summer home. 
Love affairs were in full progress during our stay, and the 
amorous exclamations of the males could be heard at a distance 
exceeding 300 yards, even in the thick forest. Being told by 
the natives that the largest tortoises were on the top of the 
mountain we took a couple of burros and went up to secure the 
largest specimen obtainable. The shell of the one selected is 
shown in the photograph, on the back of a burro. It was nec- 
essary to skin this animal, for the reason that even two burros 
could not carry such a specimen alive. 
In a little valley, 10 miles from the ranch, and but a short 
distance from the mountain’s top, we found a number of big 
fellows, considerably larger than any seen at the lower altitude 
around the ranch. This valley was undoubtedly the home of the 
patriarchs of the mountain, and a better spot for their develop- 
ment could not be found. ‘There were several deep ponds of 
water, and judging by the number of cattle present, the grass 
was of the sweetest. The absence of female tortoises at this 
height was very noticeable, not over half a dozen being seen 
out of probably 75 individuals observed. Whether the wild dogs, 
which are so numerous and ferocious here, have eaten the fe- 
males, or whether, as is not unlikely, they had gone lower down 
on the mountain, we were not able to determine. We saw a num- 
ber of skeletons of tortoises that the dogs had killed, and noticed 
that, as a rule, the females being the smallest were the ones 
to suffer. However, we saw a couple of males over three feet 
long, showing that when hunger is keen enough even the large 
ones are killed. The presence of these oldest and largest males 
at this elevation during the rainy season would indicate that they 
traveled but little, and after noting their surroundings we could 
see no reason why they should ever journey more than a thou- 
sand feet away from the water-holes. A constant abundance of 
