556 ON SEEDLINGS 



obtusely trigonous, distantly and minutely ciliate-serrulate, deep 

 subglaucous-green, straight in the seed, emerging as in Pinus, finally 

 radiate and straight, or more or less twisted or curved in one or two 

 directions, ri-1'7 cm. long. 



Plumule covered with a cap of scales the outer of which are 

 pale brown, the inner smaller, more numerous and hyaline. 



Stem erect, ultimately woody. 



Leaves simple, entire, cauline, acicular, spirally scattered, 

 obtusely tetragonous, narrowed at the base into a very short petiole 

 and jointed to a little pulvinus on the branches, deep green, very 

 short. 1 



CYCADACE.E. 



Benth. et Hook. Gen. PL iii. 443. 



Fruit and Seed. The male and female flowers are arranged 

 in separate cones in most genera ; those bearing the ovules are 

 generally the thicker. The scales are closely imbricated and 

 spirally arranged ; in the case of Cycas they are greatly 

 elongated and bear the ovules alternately on the lateral mar- 

 gins. They, in fact, resemble aborted leaves densely covered 

 with rusty brown hairs. In other genera the scales are very 

 short, much thickened, peltate and bear a single orthotropous 

 ovule on each side pointing towards the axis. The testa is 

 single and produced into a short tube at the micropyle. The 

 seed is large, variable in shape, and often variously angled. 

 The outer layer of the testa is orange or red, and the inner 

 crustaceous or bony. Endosperm is copious and fleshy, em- 

 bedding the subcylindrical embryo in its upper part; and 

 the cotyledons are conferruminate or amalgamated in one 

 piece, or free at the base only to permit the exit of the plumule. 



Seedlings. As the seeds are large in nearly all the genera 

 of the Order and differ in this respect from the Gnetaceae and 

 Coniferae, so I find that in all the seedlings observed the coty- 



1 Tubeuf, 1. c. pp. 90-92, describes seedlings of Picea excelsa, fig. 121; 

 P. alba, fig. 122 ; P. polita, P. orientalis, fig. 123 ; P. Alcockiana, fig. 124 ; 

 P. Omorica, P. sitchensis, fig. 126 ; all of which bear a general resemblance to 

 that of P. orientalis. 



