NOMENCLATURE 
7 
that of the species. Generic names are not duplicated within the sphere 
of zoology, nor are specific names within the genus. Thus, the American 
Robin is Turdus migratorius , that is, that species of the genus Turdus that is 
named migratorius. Other species of Turdus have other specific names. 
The three objects of scientific nomenclature are exactitude, univer- 
sality, and permanence. To this end the naming of zoological material is 
subject to strict laws whose principles are universally accepted and applied 
according to strict codes. Under these law r s the scientific name of a species 
is not a matter of personal preference, but is fixed so that few or none can 
dispute it, and only such changes can be made in scientific nomenclature 
as are necessary to correct current mistakes in the application of the laws 
of the code. With increased knowledge it has become necessary to depart 
slightly in letter, though not in spirit, from the strict binomial system of 
Iinnseus, and by adding a third term as name of the subspecies to make 
it a trinomial one. Wherever a three-term name is used, it is that of a 
subspecies. The first specimen described, or the first specimen to which a 
name has been attached, is regarded as the so-called “Type” form. In divid- 
ing a species into subspecies the form which was first named as a species is 
automatically given precedence and its subspecific name is a repetition of 
its specific name. Thus the American Robin that was first described and 
specifically named by Linnaeus in 1766 as migratorius , when mentioned 
subspecifically in distinction from the Southern Robin or the Western 
one becomes Turdus migratorius migratorius. The Western Robin, first 
separated by Ridgway in 1877, was named by him Turdus migratorius 
propinquus , and the Southern Robin was named Turdus migratorius 
achruslerus by Batchelder in 1900. In practice, where the generic or 
specific names are evident from the context, it is customary to indicate 
them by initial, as T. migratorius, or T.m. migratorius. 
GEOGRAPHICAL DISTRIBUTION 
The broader facts of the geographical distribution of life are patent 
to the most casual observer. The primary divisions of distribution, the 
Tropics, Temperate, and Arctic zones, are obvious, but closer study shows 
within these broad divisions, minor and less obvious ones. In America, 
north of the Gulf of Mexico, there are three life regions, roughly coinciding 
with the above, called the Tropic, the Austral, and the Boreal. These are 
subdivided into life-zones each characterized by its own peculiar assem- 
blages of plants and animals. 
The Tropic region is sufficiently characterized by name and need be 
only mentioned. 
The Austral region corresponds roughly to the popular geographical 
conception of the Temperate zone. It is divided into three life zones, the 
Lower Austral, the Upper Austral, and the Transition. The Lower Austral 
might be designated as subtropic; it includes the Gulf of Mexico and the 
south Atlantic states, but does not reach Canada. The Upper Austral is 
the first zone in which we in Canada are directly interested. In the east, 
it merely crosses the border on the Lake Erie shore and includes the famous 
Niagara fruit belt. In the west it touches our southern boundaries in 
Saskatchewan and perhaps adjacent parts of Manitoba and Alberta and 
penetrates into British Columbia along the southern fruit-growing valleys. 
The northernmost Austral or Temperate life-zone is the Transition, which 
includes the greater part of the highly cultivated areas of Canada. In the 
