CENTRES OF DISPERSAL 
175 
States among an almost semi-tropical fauna of colossal 
sloths, peccaries and other southern forms that have long 
since vanished, and which lived through it all in close proxi¬ 
mity to the supposed ice-sheets and arctic climates. The great 
majority of the Pleistocene deposits in the north indicate that 
the country had a milder climate during the Ice Age than at 
present, and this is particularly shown by those containing 
plant remains. As plants are supposed to he more trust¬ 
worthy guides than animals, as indicators of former climatic 
conditions, T will give one more example of a Pleistocene 
deposit from the southern States which has come to my know¬ 
ledge. 
A Pleistocene deposit in north Carolina examined by Pro¬ 
fessor Berry * yielded no boreal or even cool temperate 
plants. Hence it may safely be concluded, he thinks, that 
the temperature of the Pleistocene Period in the same latitude 
was not lower than it is now. If anything, he says, it was 
slightly higher. Additional facts pointing to the same general 
conclusion are the former more northward extension of the 
cypress (Taxodium distichum) and of Planera aquatica. That 
these plants did not flourish during mild inter-Cflacial phases 
of the Glacial Epoch, remarks Professor Berry, is indicated 
by their being associated in Maryland with ice-borne boulders 
of considerable size. 
To return once more to southern Florida, we find that what 
we observed among plants, namely, the tropical element, is 
likewise recognisable in the fauna. According to Dr. 
Merriam f the semi-tropical insect fauna of southern Florida 
comprises in all not less than a thousand species of Antillean 
insects, half of which are beetles. 
Among the mollusks there are a number of Antillean genera 
represented in southern Florida, such as Chondropoma, 
Liguus, Cepolis, Varicella, and others spoken of by Dr. 
Pilsbry as Mexican genera, such as Eglandina, Praticolella 
and Drymaeus (dormani type). Dr. Pilsbry regards only the 
last group as genuine natives of the soil. He believes that 
their ancestors entered Florida at the close of the Miocene 
* Berry, E. W., “ Pleistocene Flora of Carolina,” p. 347—348. 
t Merriam, C. H., “ Distribution of Life in North America,” p. 53. 
