162 TRANSACTIONS OF THE [Sess. lxxxvii 



hypocotyl protrudes, eventually coming above the soil level 

 (figs. 4, 5, and 6). It is then seen that the bending is such that 

 one cotyledon is directly above the other as they are withdrawn 

 from the testa (fig. 7). Germination, then, is epigeal. 



A straightening of the hypocotyl next ensues, and, as this 

 process is nearing completion, the cotyledons begin to expand 

 (figs. 8 and 9). Meantime, from the blunt lower end of the 

 hypocotyl, which becomes tinged with red, there grow out 

 numerous unicellular hairs. Avhich act as would root hairs in 

 the double function of fixation and absorption, though the 

 former is probably their primary function in the natural habitat 

 of the plant. This production of hairs from the hypocotyl 

 conforms with the behaviour during germination of the macro- 

 podous embryos of typical helobic plants, and is, no doubt, 

 correlated with the slow development of the radicle and the 

 more immediate need of fixation. The radicle begins to show 

 growth only after a perfect mat of these hairs has been pro- 

 duced round and above its area of attachment to the hypocotyl. 

 Its further development, once initiated, seems to be fairly 

 rapid, and later it bears a few root hairs in the usual definite 

 area (fig. 10). The expanded cotyledons are only slightly 

 larger than they are in the seed, and each now shows a very 

 short petiole slightly thickened at its insertion on the hypo- 

 cotyl. There is a very indi.stinct midrib in the cotyledon 

 and a rather more noticeable apical indentation. 



Although germination is quick, the seed coat being split 

 on the fourth or fifth day, the plumule is slow in evolving, 

 and is just discernible in seedlings about five weeks old 

 (fig. 10). Following this stage growth is very slow, and after 

 seven months the seedling has just produced its seventh leaf. 



The first leaf produced is small, obovate, retuse and entire, 

 with a distinct midrib but no other discernible venation. 

 The second leaf dift'ei's, apart from its gi'eater size, in having 

 no apical indentation. The third tapers towards the base, 

 is elliptical or oval, acute and entii'e, or may have one or two 

 small teeth on each side. The ultimate leaves are variable, 

 usually elli])tical, acute, sometinics very shortly cuspidate, 

 and are increasingly serrulate. All the leaves are a fresh 

 shining green colour above, glaucous beneath, glabrous, 

 simple, alternate, and petiolate. From the tliird leaf onwards 

 they are alternately incurvinerved (fig. 1 1 ). 



