872 
ORIGIN OF LIFE IN AMERICA 
Argentina. It seems manifest, therefore, that the ancestral 
members of this sub-family have travelled along the west 
coast of South America probably from a southern centre of 
dispersal. We find no trace of them in Central America or the 
Antibes, but it is in North Africa where we meet with 
Ctenodactylus with its peculiarly modified inner toes. Here 
in the Mediterranean region, and not in Africa proper, must 
have been die Old World centre of dispersal, for we find the 
allied extinct genus Pellegrinia in the Pleistocene of Sicily, 
and Ruscinomys in the Pliocene of southern France. A 
recent relation of Ctenodactylus (Massoutiera) has passed 
southward towards the Senegal. The main branch, however, 
has apparently invaded eastern Africa from the Af editorn nean 
region, giving rise to the genera Pectinator, Thryonomys and 
Petromys. Only a single species (Thryonomys swinderianus) 
has gained the west coast of Africa. Of the sub-famdy 
Echimyinae, which largely inhabits Brazil, Africa possesses 
no near relations. The only African family of the hystrico- 
morphous rodents, that of the Cape jumping hares (Pede 
tidae), occupies a more isolated position, its exact relationship 
being still somewhat obscure. But in any case, I fail to 
deduce sufficient evidence from the distribution of these 
hystricomorphous rodents, in favour of a direct land connec¬ 
tion between South America and Africa, although there must 
have been one between the Mediterranean region and W estern 
South America by way of the West Indies and Central 
America (see p. 280 and Fig. 14). 
Apart from the cape jumping hares (Pededitae), there ai’e 
in South Africa certain mammals which indicate a distant 
relationship with South American ones. The peculiar pig- 
like African edentate Orycteropus occurs in Africa, while 
another edentate, the pangolin (Manis), inhabits Africa and 
the Indian region. Dr. Tullberg thought that these and other 
features implied that south-western Africa must have been 
joined by land to South America during a time when the 
former was completely severed from the rest of Africa. But 
even this land bridge ceased to exist, according to Professor 
Tullberg,* at the beginning of the Tertiary Era, at latest in 
* Tullberg, T., “ System der Nagetiere,” p. 49S. 
