125 



size of the latter, and their lobed appearance is due to their being deflexed and growing in a lateral direction 

 till they reach the base of the seed, while their apical edge becomes coiled round the radicle. The middle 

 portion through which the midrib runs cannot coil round the radicle, and is therefore short, thus giving 

 rise to the apical sinus. This will be better understood by reference to the seedlings. A closely similar 

 or identical case occurs in E. marginata, a transverse section of which shows the manner of coiling round 

 the radicle. Although the section showing the coil is transverse to the seed, it is really through the 

 longitudinal plane of the cotyledons. E. stelhtlata (fig. 341, not reproduced) has very much smaller and 

 narrower seeds, and the coiling is therefore less extensive. The radicle is club-shaped, thickest at the 

 point, and central to the cotyledons. . . ." 



He describes at length the embryo of two species : 



E. globulus : " Straight, or nearly so, fleshy, colourless, occupying the whole interior of the seed, 

 and conforming to it in general outline; cotyledons broader than long, deflexed and convolute over the 

 radicle, which the lobes equal in length ; half of one cotyledon lies over half of the other, and consequently 

 only one-half of each cotyledon lies against the testa ; radicle long, stout, fleshy, truncate, at the end where 

 it lies against the testa, otherwise wholly enclosed by the longitudinally coiled cotyledons, parallel with 

 the axis and consequently some distance from the hilum." (i, 530, with fig.) 



E. stellulata : " Straight, filling the interior of the seed, colourless ; cotyledons transversely oblong 

 convolute and folded round the radicle; radicle long, stout, truncate at the apex, occupying the centre 

 of the seed and enveloped by the cotyledons." (p. 532.) 



Dr. Cuthbert Hall in Proc. Linn. Soc, N.S.W., xxxix, 476, 1914, says: 



" Embryo. — As endosperm is not present, the form of the embryo depends on the shape, size and 

 manner of folding of the cotyledons. The length of the petioles in the embryo depends on the distance 

 from the junction of lamina and petiole to the superior pole of the radicle ; and, in most species, is probably 

 fairly short before germination. In E. citriodora and E. maculata, the cotyledons are almost sessile. In 

 E. marginata, the hypocotyl is subterranean, and the failure of this to elongate, by growth in germinationi 

 is compensated for by the great elongation by growth of the petioles, so as to raise the laminse well above 

 the ground. A similar condition obtains in Angophora cordifolia, where the hypocotyl is short, and the 

 petioles long. E. calophylla and E. Todtiana also have fairly long petioles." 



See also the subject of the folding of the cotyledons in the embryo at p. 518, 

 and compare with Lubbock"s remarks already quoted above. 



I had prepared some notes, but found that the subject required a series of enlarged 

 drawings of embryos, which Miss Flockton has had no time to do. I commend the 

 subject to the attention of a student. 



