366 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
vascular nature of the organic elements composing the mass. The whole struc- 
ture recalls to one’s mind the appearance given by longitudinal sections of the 
xylem portion of the vascular area of a gymnosperm, such as Pinws. Only the 
xylem area is represented in the specimen, no traces of medullary, cortical, or 
phloem tissue being visible. Medullary rays are present, as shown in the 
microphotograph. 
The xylem itself is composed of a homogeneous mass of vessels, tracheidal in 
nature, no differentiation as regards the vascular elements being present. In 
places one may readily make out in longitudinal sections dark opaque bands of 
much greater size individually than the tracheides. These, in all probability, 
represent resin passages belonging to the xylem. It would seem, further, that 
these masses might be considered as being nothing more than an aggregation of 
material similar in nature to that of the walls, and due to changes under the 
process of petrifaction. This, however, is opposed by the fact that they occur 
even in these small sections fairly commonly and at the same time are all of 
exactly the same size as regards width. At all events, they represent some 
definite structure, and in all probability resin passages. 
The walls of the tracheides themselves, seen under the high power of the 
microscope, appear to be pitted; but the preservation is by no means good 
- enough to warrant any remarks on this, beyond that in the common wall of 
adjacent tracheides occur clear spaces of the same relative importance as the 
bordered pits of such a gymnosperm as Pinus. These clear spaces occur regularly 
along the length of the tracheides, and stand out strongly against the dark 
color of the walls in their preserved condition. 
The nature of the xylem itself leads to the conclusion that it is a portion of 
a gymnospermous plant, resembling stronglv in nature the same portion of a 
coniferous plant. 
The meteorological observations taken during our stay in the 
Antarctic have yet to be studied, and only tentative conclusions have, 
so far, been reached. Systematic observations were taken during the 
voyages of the Vimrod between New Zealand and MacMurdo Sound, 
and at Cape Royds observations were recorded at intervals of two 
hours from March, 1908, to February, 1909. During this period no 
rain fell. The lowest. temperature definitely recorded was —57° F. 
near White Island on the Great Ice Barrier on August 14, 1908. We 
were able to secure interesting observations of the upper currents of 
the air at Ross Island. Reporting on this subject, Professor David 
and Lieutenant Adams state: ; 
At Mount Erebus our winter quarters were situated in an exceptionally 
favored position for observing the upper currents of the atmosphere. Not only 
had we the great cone of Erebus to serve as a graduated scale against which 
we could read off the heights of the various air currents as portrayed by the 
movements of the clouds belonging to them, but we also had the magnificent 
steam column in the mountain itself, which, by its swaying from side to side, 
indicated exactly the direction of movement of the higher atmosphere. More- 
over, during violent eruptions like that of January 14, 1908, the steam column 
rose to an altitude of over 20,000 feet above sea level. Under these circum- 
stances it penetrated far above the level of a current of air from the pole 
northward, so that its summit came well within the sweep of the higher wind 
blowing in a southerly direction, the result being that the steam cloud in this 
