104 
T. G. HALLE, 
(Schwed. Südpolar-Exp. 
best known in the whole Jurassic. There is no reason, however, to believe 
that the Hope Bay flora is in any considerable degree either older or 
younger than those known to be of Middle Jurassic age. 
The chief interest of the Hope Bay flora is connected with the facts that it is 
the first Mesozoic flora known from the Antarctic, and that it is very far removed 
from all other contemporaneous floras. It becomes therefore a factor of great im- 
portance in considerations of climatic and phyto-geographical conditions during the 
Mesozoic Era. The first question to be settled before entering upon any such dis- 
cussions regarding any fossil flora is whether the plants are preserved in the vicinity 
of their habitat or may have been transported from a long distance. In the dis- 
cussions of the Arctic floras as indicators of the past climatic conditions in the Arctic 
Zone, several authors have claimed that the plant-remains may have drifted from more 
southerly latitudes. It is only by critical analysis of the mode of occurrence of the 
Arctic floras, chiefly by Prof. NathorST (1910), that their preservation in situ can be 
regarded as proven. In the Antarctic, every evidence that could serve as a basis 
for discussions of past climates, was wanting, until the Swedish Antarctic Expedition 
of 1901 — 1903 brought home the first fossils of any importance. Almost all the 
fossil plants from the Antarctic belong to one of the two floras; the Tertiary flora 
of Seymour Island and the present Jurassic flora of Hope Bay. In regard to the 
mode of deposition of the Seymour Island flora there have been different opinions. The 
plant-remains are very fragmentary, as a rule, and show evidence of having under- 
gone some transport before being deposited. Since they occur in a marine series 
of sediments, therefore, it is not unnatural to suppose that they may have drifted 
to the present locality from afar with the currents. P. DuSEN, in his description of 
the Seymour Island flora, does not accept the theory of transport in this manner of 
any portion of the same from another climatic zone; and it must be admitted that 
if a fairly rich, though fragmentary, flora is found in a deposit which has been laid 
down in the shallow water close to a coast, the probability is that it is derived from 
that same coast and not from any far-away land. Yet, the matter cannot be said 
to be clear in regard to the Tertiary flora of Seymour Island. If the Jurassic flora 
of Hope Bay is preserved near its original habitat, it is therefore the only flora at 
present known which gives any reliable information on the past climate of the Ant- 
arctic region. J. G. Andersson has already stated (1906, p. 27) that the plant- 
bearing deposit probably is of lacustrine origin, mentioning as evidence, ùiter aha, 
that the few fossil mollusca seem to be a freshwater form. The occurrence of 
Sagenopteris, quoted in this connection, cannot be held to be of much importance, 
because it is not quite proved, that this type of frond belongs to a water fern; and 
