We have already considered the evidence pointing to the conclusion that systems of volcanoes, like that of the Lipari Islands, are similarly ranged along lines of fissures, and there is equally good ground for believing that the great linear bands of volcanoes, which, as we have seen, stretch for thousands of miles, have had their positions determined by great lines of fissure in the earth's crust. While, however, the smaller fissures, upon which rows of scoria-cones are thrown up, seem to have been in many cases opened by a single effort of the volcanic forces, the enormous fissures, which traverse so large a portion of the surface of the globe, are doubtless the result of numerous manifestations of energy extending over vast periods of time. The greatest of these bands along which the volcanic forces are so powerfully exhibited at the present day, is the one which stretches from near the Arctic circle at Behring's Straits to the Antarctic circle at South Victoria. The line followed by this volcanic band, which, as we have seen, includes more than one half of the active volcanoes of the globe, is a very sinuous one, and it gives off numerous offshoots upon either side of it. The great focus of this intense volcanic action may be regarded as lying in the district between the islands of Borneo and New Guinea. From this centre there radiate a number of great lines, along which the volcanic forces are exhibited in the most powerful manner. The first of these extends northwards through the Philippine Isles, Japan, the Kurile Islands, and Kamtschatka, giving off a branch to the east, which passes through the Aleutian Islands and the peninsula of Alaska. This band, along which the volcanic forces are very powerfully active, is continued towards the south-east in the New Britain, the Solomon Islands, Santa Cruz, the New Hebrides, New Zealand, and South Victoria. East and west from the great central focus there proceed two principal branches. The former of these extends through the Navigator Islands and Friendly Islands as far as Elizabeth Islands. The latter passes through Java, and then turns north-westward through Sumatra, the Nicobar Islands, the Andaman Islands up to the coast of Burmah. The great band which we have been describing exhibits the most striking examples of volcanic activity to be found upon the globe. Besides the 150 or more volcanoes which are known to have been in a state of activity during the historical period, there are several hundred very perfect volcanic cones, many of which appear to have but recently become extinct, if indeed, they are not simply in a dormant condition. For long distances these chains of volcanic cones are almost continuous, and the only very considerable breaks in the series are those between New Zealand and the New Hebrides on the one hand, and between the former islands and South Victoria on the other. [Sidenote: GREAT VOLCANIC BANDS OF THE GLOBE.]