CXXXI1V 
to the Dey in money and goods, particularly armaments, as 
also did the U.S. of America. It was in 1830 that the power 
of the Dey of Alger was definitely broken and that the country 
entered on a new era. I have briefly alluded to these historical 
facts, as the traces of the various conquests and attendant 
destruction are found all over Algeria and are one of the 
outstanding features of the country, and because the historical 
events which have passed over this region have had on the 
fauna an effect on the whole as beneficent as it was disastrous 
for the human races. 
The African continent resembles in general outline South 
America so closely that one might be inclined to look upon 
North Africa, with regard to the fauna and flora, as_being 
as much a part of Africa as the Guianas, Venezuela and 
Colombia form part of South America. The larger Algerian 
animals, those which appeal most to the imagination, the 
lion, leopard, hyaena and ostrich, are indeed closely associated 
in our mind with tropical Africa. When, however, we more 
critically examine the fauna of Mauretania, a very small 
percentage of the species of Algeria will be found to be really 
of Ethiopian descent. There are two factors which place 
North Africa faunistically in quite a different position from 
the northern countries of South America: Mauretania has 
about the same latitude as Texas and North-West Mexico, and 
it is separated from tropical Africa by a wide desert belt, 
which is as effective a barrier as a wide expanse of sea. Both 
these factors act in the same direction, joining North Africa 
in climate and geographical continuity or propinquity to the 
Mediterranean countries of Asia and Europe rather than to 
tropical Ethiopia. It therefore affords better conditions for 
immigration from the east, west and north than from the 
south, and for a corresponding extension of the Mauretanian 
indigenous species. For the composition of the fauna of a 
country is determined mainly by accessibility at least in 
former periods and by the suitability of the conditions of life 
now and in former epochs. Though the Mediterranean Sea 
looks a formidable barrier on the map, it has not prevented 
North Africa from being mainly inhabited by species of 
Palaearctic origin, many of which have come into Mauretania 
