548 ON SEEDLINGS 



nearly so, spreading, decussate, and nearly flat. The first 

 pair are lanceolate-linear and acute ; the next two pairs are 

 linear and subacute ; while the fourth and fifth pairs are 

 linear, cuspidate, and unequal in size, as if really alternate 

 and scattered, and such in fact may be the case. The leaves 

 of lateral branches in the seedling resemble those of the 

 adult in being scattered with a distichous arrangement, while 

 the phyllotaxy remains the same. On ascending or upright 

 shoots they ascend in various directions, and are not bifa- 

 riously arranged. All have a distinct midrib seen on both 

 surfaces, but more prominent on the upper, are distinctly 

 petiolate, and arise from a linear-oblong, elevated pulvinus 

 or process adnate to the shoot. 



The cotyledons of Thuya occidentalis are linear, acute, 

 tapered to the base, one-nerved, flat or nearly so, and two 

 in number. The two first leaves are opposite, spreading, 

 similar to, but smaller than the cotyledons, and are followed 

 by five or more whorls of three similar ones. In some cases 

 one of the three is inserted at a slightly higher level than the 

 rest, or they may even all be scattered with a spiral arrange- 

 ment. The ultimate leaves are opposite, decussate, and adnate 

 for great part of their length to dorso-ventrally flattened shoots. 

 The cotyledons of Thuya gigantea (fig. 676) conform to the 

 above type. The first four leaves are in opposite pairs de- 

 cussating with the cotyledons, and are followed by a number 

 of whorls or pseudo-whorls, of similar but longer and more 

 decidedly acicular leaves. Above the first dozen or so of 

 whorls, lateral branches are given off bearing sometimes a few 

 acicular and spreading leaves at their bases, while succeeding 

 leaves are imbricate and decurrent, gradually giving place to 

 closely imbricate and decurrent leaves, arranged in four rows 

 and decussate. The branches are then horizontal or droop- 

 ing, and dorso-ventrally flattened. 



Cryptomeria japonica differs from the above-mentioned 

 species in having two to three linear, obtuse cotyledons flat 

 above and slightly convex beneath. Out of fifteen seedlings 

 examined, twelve had three cotyledons. The testa is very 

 frequently carried up on the tips of the cotyledons during 

 germination, but is ultimately thrown off by their bulging 



