Its ready accessibility from the metropolis is the chief factor in its popularity.
The San Pedro, Los Angeles & Salt Lake railway, also an important factor in east and west transcontinental traffic, opened in May 1905, has been of special value in the development of the southern part of the state.
The export, moreover, of live sheep and of frozen mutton to Europe has become an important factor in the trade of Argentina.
The short period of this evolution is at least one factor in the primitive grade of even the most specialized members of the group. In the advance of their molar teeth from a tritubercular to a grinding type, the author traces a curious parallelism between marsupials and placentals.
The vertical relief of the land above the ocean is a very important factor in determining the climate as well as the distribution of the fauna and flora of a continent.