Reviews—German South Polar Expedition. 87 
not in existence in its present form during the basaltic eruptive 
period, yet it is believed that the shape of the present crater is to be 
explained through an explosive outburst rather than subsidence. As 
regards the lavas and tuffs of St. Paul, it is impossible to speak of 
the period of their origin with certainty, because of the absence of 
any tossil-bearing sediments. Probably a part of the eruptive period 
belongs to Tertiary, another to Quaternary and later times. It 
is impossible, however, to know where the Tertiary portion ends 
and the other begins. An examination of the Dumas crater of New 
Amsterdam revealed evidences sufficient to support Vélain’s results im 
all essential details. The crater cone and the lava streams which ran 
from it have quite a fresh appearance ; the eruptions were undoubtedly 
still in progress during historical times. The late period of eruption 
of the lava streams accounts for the favourable landing facilities near 
the Dumas crater, for the wave action has not had time to cut a steep 
wall in the lava. Lateritic weathering products, which play such an 
important part on the island of St. Paul, are absent. This fact also 
speaks for the recency of eruption in the Dumas crater. . In some 
parts of the lava, cavities, often 8 to 10 metres broad, twice the ‘same 
measurement in height, and over 200 metres long, were met with. 
From the roofs of these caves hang lava stalactites of fantastic shapes. 
According to Vélain the cavities are due to gases which collected under 
the lava stream and afterwards forced their way through it. The 
present-day vulcanologist generally explains such a phenomenon as 
the result of the coating of the upper layer of the lava stream by a non- 
yielding outer crust; the inner portion of the stream, moving forwards, 
would leave behind a hollow cavity. Some of the cavities observed 
by the present expedition were undoubtedly the result of gaseous 
accumulation. 
Dr. Reinisch discusses the chemical relationship of the basalts of 
St. Paul, New Amsterdam, Kerguelen, Heard, and Possession Islands. 
Rhyolite tuff, basalts, and siliceous sinter are found on St. Paul; only 
basalts of various constitution are known on New Amsterdam, basalts, 
phonolite, and trachyte on Kerguelen, and basalts on Heard and 
Possession Islands. Very instructive tables and diagrammatic pro- 
portional representations of the chemical constituents of the rocks are 
given. 
Dr. Vanhoffen treats of the plants and animals of St. ‘Paul and 
New Amsterdam in an exhaustive manner. A comparison of the 
faunal lists of the two islands shows a certain agreement. This 
agreement would probably be found on closer investigation to be still 
greater than appears at present. It is also seen that the number 
of peculiar forms is few and that no close relationship exists with the 
animal life of the neighbouring sub-Antarctic islands. Hence it is 
inferred that the fauna is an accidental and not an original. one, and 
that it has been affected by human interference. 
The report is illustrated by three plates of eight photographie views 
and several text-illustrations. 
Ivor THomas. 
