Scott and Mas ten . — The Structure of Trigonocarpus. 117 
PI. XI, Fig. 8, is another transverse section from the same specimen as 
that shown in Fig. 7, but it is cut at a considerably higher level across the 
micropylar beak. The sclerotesta, s.t has become thinner and the ridges 
are less developed. The triangular form of the micropyle, ton., is still pre- 
served, although it is no longer equilateral, one side being somewhat shorter 
than the others. The wing-like form of the sarcotesta is clear, but there 
has been much loss of tissue and consequent deformation. Allowing, as 
before, for the overlap on the shorter side, the total spread of the wings 
would be the same as before, about 21 mm. In some places the sarcotestal 
tissue, with the exception of the limiting layers, has entirely disappeared, 
and the two surfaces of the wing are pressed together. 
PL XII, Fig. 9, is another transverse section from the same specimen as 
Figs. 7 and 8, but is cut at a still higher level. The sclerotesta, s.t., is 
here very much reduced in quantity, and evidently at a slightly higher level 
it would disappear altogether. The micropyle, t.m ., is still triangular, and 
the departure from the equilateral form is still more marked than in Fig. 8. 
The total spread of the ‘wings’ is almost exactly equal to that of Figs. 7 
and 8. 
PL XII, Fig. 10, is from another slide cut from the same specimen as 
the others. Sclerotic tissue, s.t., around the micropyle can still be seen, 
although it is quite small in amount. There is now no sign of a triangular 
micropyle, but its place is ! taken by a slit ; however, it is quite evident that 
in this part of the seed, owing to the small amount of sclerotic tissue, 
a triangular micropyle might readily have been converted into a crevice by 
crushing from without. Compared with the lower sections, the micropylar 
boss in this slide is not well defined, while the whole structure varies 
irregularly in thickness, 'owing partly to collapse consequent on disappearance 
of tissue, and partly to the intrusion of Stigmarian rootlets. The best- 
preserved part of the wing, however, does not look as if much loss of tissue 
has taken place. 
The section shown in PL XII, Fig. 11, from another seed, is the highest 
of our transverse series, and is cut, apparently, near to the extreme tip 
of the micropyle. This figure is magnified about thirty-two times, or about 
five times the scale of the other figures in this transverse series. The 
limiting layers, epidermis, e., and hypodermis, h., are quite well preserved, 
and the inner tissues are fairly well so. The micropyle appears to be 
nearly or quite closed, and is surrounded by a little group of brown cells, b., 
not more than 300 fx in diameter, and that by a light zone, /., the maximum 
diameter of which is not more than 400 /x, so that the whole is on an 
extremely small scale. This section apparently shows more than half the 
circumference of the micropylar tube, and as the maximum distance from 
the centre of the micropyle to the outside of the testa is only 1-2 mm. there 
is no question of a wing, unless one supposes that the micropyle is entirely 
