IN THE WAKE OF THE “ CHALLENGER.’ 
5 
A portion is then to be boiled in vacuo , the gases collected, and 
their volume determined, part being hermetically sealed in glass 
tubes. The gases contained in the air-bladder of certain tishes 
should be examined. 
Botany . — The duties of the botanist are twofold: 1. To 
collect. 2. To make observations on the life, history, and 
structure of certain plants. The vegetation of oceanic islands 
is of especial importance, these being sometimes the last 
position of flora of great age, which are liable to be speedily 
exterminated, as at St. Helena. A collection should be made 
from each islet of a group, as the floras of contiguous oceanic 
islands are wonderfully different. Among islands of which the 
flora is absolutely or almost unknown are : — Fernando de 
Noronha; Trinidad and Martin Yaz, off Brazil ; Socotra; Prince 
Edward I. ; Crozets ; Marion I. ; Pitcairn, Boiinty and Mac- 
quarie Islands. With regard to the Indian Archipelago, Java 
alone has been explored, and the Philippines but partially. 
Collections from islands east of Java, especially Lombok and 
New Guinea, would be very valuable. The part played by 
icebergs in the transportation of plants is of importance, and 
the algae in hot-springs should be examined. 
Zoology . — The littoral fauna of the Papuan shores of Torres 
Straits is important for comparison with the fauna of the 
opposite Australian shore. 
A hydrographical examination should be made of “ Wallace’s 
line ” in the Malay Archipelago, and of the littoral faunas on 
either side of it. Soundings should be taken in the Celebes 
Sea, Capt. Chimmo having found in 2,800 fathoms a mud 
bottom of Radiolaria and sponge-spicules, but no calcareous 
organisms. 
A line of soundings between Japan and Vancouver’s Island, 
and between the latter and Valparaiso, would be useful for in- 
vestigation of the quadrant-like zone of the Pacific which 
separates the eastern boundaries of the Polynesian archipelago 
from the coast of Northern Asia and America. 
The limitation of reef corals should be investigated. It has 
been suggested that the limit of twenty fathoms may be a 
thermal one. Specimens of the hair of unmixed races of men 
should be collected. 
Before entering generally and in detail into the results of 
the expedition, so far as they have been accomplished, it will 
be interesting to follow, as best we can, in the wake of the 
gallant ship during her cruise, picking up such 46 flotsam and 
jetsam” as may be accorded to us. 
At 11.30 a.m. of Dec. 21, 1872, H.M.S. Challenger cast off 
the jetty, at Portsmouth. There was a strong breeze blowing 
from the S.W., and the storm-drum was hoisted. This ship, 
