OCR Text |
Show 608 MR. P. C. MITCHELL ON A FORMULA TO [Nov. 4, be drawn with four strokes of the pen thus indicates the regions in their relative positions, fig. 1. Fig. 1. Nearctic. Neotropical. Palasarctic. Ethiopian. Oriental. Australian. The four subregions in each region except in the Nearctic region lie, in a general way, two to the north, two to the south, two to the east, two to the west. In the Palaearctic region, for instance, the North-European and Siberian subregions are the northern pair; the Mediterranean and Manchurian the southern pair ; the North- European and Mediterranean are the western, the Siberian and Manchurian the eastern subregions. If the subregions are numbered thus:- North-European 1 Mediterranean 2 Siberian 3 Manchurian 4 and if the numbers be placed as indicated in figure 2, it will that the numbers are in the relative position of the regions they denote. Fig. 2. 1 2 3 4 The numbers 1, 2, 3, 4 are placed in similar relative position in the spaces corresponding to the other regions except the Nearctic, and obviously represent subregions as in the following list:- ETHIOPIAN REGION ORIENTAL 1. West Africa. 2. South Africa. 3. East xlfrica. 4. Madagascar. 1. Hindostan. 2. Ceylon. 3. Indo-China. 4. Indo-Malay. |