8 
nomial system of Linnzus, 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 of the original binomial form. The first 
specimen described, or the first specimen to which a name has been at- 
tached, is regarded as the so-called ‘“‘ Type” form. Therefore, in dividing 
a species into subspecies the form which was first named as a species 
becomes automatically the type race, and its subspecific name is formed 
by a repetition of its specific name. Thus the American Robin that was 
first described and specifically named by Linnzus in 1766 as migratorius 
when mentioned subspecifically in distinction from the Southern Robin or 
the western one becomes Planesticus migratorius migratorius. The Western 
Robin first separated from it by Ridgeway in 1877, was named by him as 
Planesticus migratorius propinquus, and the Southern Robin by Bachelder 
in 1900, is Planesticus migratorius achrusterus. In practice,where the generic 
or specific names are evident from the context, it is customary to indicate 
them by initial, as P. migratorius, or P. m. migratorius. 
Subspecific varieties are divisions of the species and, except in special 
lines of work, or where special exactitude is necessary, of minor importance. 
As these subspecies are also often based upon points of difference only 
perceptible to the most experienced observers, they generally lie outside 
the sphere of interest of the average amateur observer. 
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 
that within these broad associations minor and less obvious ones can be 
detected. In America, north of the gulf of Mexico, there are three life 
regions, roughly following the above, called the Tropic, the Austral, and 
the Boreal regions. These are subdivided into life zones each characterized 
by its own peculiar assemblages 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 zones. The 
Lower Austral might be designated as subtropic and extends north includ- 
ing the gulf and the south Atlantic states, not occurring in Canada at all. 
The Upper Austral is the first that we are directly interested in in eastern 
Canada, it merely crosses the border on the lake Erie shore and includes 
the famous Niagara fruit belt. The frequent or regular occurrence of 
numerous southern species on Pelee point in Essex county, Ontario, marks 
the strongest development of this zone in the Dominion. It slightly touches 
our southern boundary again in Saskatchewan and perhaps some of the 
warmer valleys running into southern British Columbia. The northern- 
most Austral or Temperate life zone is the Transition zone which includes 
the greater part of the more highly cultivated areas of Canada. It occupies 
the shores of the bay of Fundy, the upper St. Lawrence river, southern 
Quebec and Ontario, the lower sections of the prairie provinces, and a 
