REVISION OF THE GENUS PINUS. 365 
The property of the pine-pollen to float for a long time in the air, and to be carried by storms 
to very distant localities, is well known. I have found in streets of St. Louis after a rainstorm from 
the south, in March when no pines north of Louisiana were in bloom, pine-pollen which must have 
come from the forests of P. australis on Red river, a distance of about 64 degrees of latitude or 400 
miles in a direct line. 
The FEMALE FLOWER consists, as in all Abietinew, of a carpellary scale in the axil of a smaller, 
concealed bract, bearing two pendulous ovules on the lower part of the upper side. A number of 
such scales in the axils of their supporting bracts, and spirally arranged, form the female ament. 
The question of the nature of the scales, and of the ovules they bear, is not to be discussed here, but 
it may be stated that the best lights force the view on us that the carpellary scale consists morpho- 
logically of two leaf-organs, lateral to an undeveloped axis and united at their posterior edges (those 
turned towards the axis of the ament), and thus bearing their naked ovules on their morphologically 
outer but now reversed and apparently upper side. 
The carpellary scales,.which in the flower as well as in the fruit we call, in short, scales, [170] 
are either rounded, obtuse, and appressed (in Strobus, etc.), or they have a short (P. resinosa, 
sylvestris, etc.) or a longer (P. ponderosa, Teda) or an elongated subulate, often squarrose, point 
(P. contorta, inops, pungens). 
The aments are globose, oval or elongated, subsessile or peduncled, single or several together, 
always erect, each borne in the axil of a bract, its base invested by sterile bracts which gradually or 
suddenly give place to the carpel-bearing bracts, just as the involucral scales of the male flowers give 
place to stamens. They make their appearance on the upper part of the year’s shoot, often just 
below the terminal bud, when we call them subterminal ; or they become /ateral, when the axis elon- 
gates beyond them, and sometimes more aments form above them in the same season. The axis 
above the aments continues covered with leaf-bundles in some, while in others it is naked for some 
distance, or rather destitute of leaves, bearing only bracts; a second stage of aments or the terminal 
bud is always preceded by a number of leaf-bundles. 
The position of the female ament, whether subterminal or lateral, seems to be connected with 
an essential difference in the species of pines, secondary in importance only to the leaf structure as 
described above, and both of these together will enable us to arrange the species in something like a 
natural order. It ought to be understood, however, that the relative position of the ament on the 
axis is not absolute and that variations do occur. Species with ordinarily subterminal aments may 
in young and vigorous shoots sometimes bear lateral aments; this occurs, though very rarely, in’ 
P. ponderosa and australis, and perhaps in others, but I have never seen it in any of the Strobus 
section, nor in P. sylvestris, resinosa, Laricio, or its allies. More frequently subterminal aments are 
found in species which normally bear lateral ones, probably when with the formation of the aments 
the vigor of the axial growth has been exhausted ; thus sometimes a second stage of aments is sub- 
terminal, while the first is of course lateral; or subterminal and lateral ones are occasionally found 
on different branches of the same tree ; or, very rarely, a tree bears almost entirely subterminal 
aments. This last case I have seen in the Californian P. mwricata and in the Mediterranean [171] 
P. Pyrenaica. This character has to be studied intelligently among the native trees in their 
homes. So long as only a few herbarium specimens can be consulted it must remain doubtful, and 
errors may creep in, especially as collectors have heretofore paid so little attention to the necessity of 
obtaining instructive specimens, which, however, are easily procured in any season of the year, pro- 
vided the tree bears at all; for always either flowers or young cones, or in spring both together, can 
be obtained. 
The compound Fruit resulting from these aments, known as the cone or strobile, matures at the 
end of the second, or in a single species, P. Pinea, of the third season ; during the first twelve months 
