470 JLPPBNDIX. 



fibres, and by lighter coloured strands which are the vascular 

 bundles (Fig. 8). 



The spore-cases are in sori at the edges of the leaflets, and 

 the margin of the leaflet is turned in towards the underside 

 to protect the young spore-cases. A section across a leaflet 

 shows a scaly strip of tissue on the inner side of the sorus 

 (Fig. 9). 



The spore-cases, spores, and prothallus are similar to those 

 of the Male Fern. 



LIFE HISTORY OF A PINE. 



The Fine Family. The Gymnospermous Flowering 

 Plants are not so highly differentiated as the Angio sperms, 

 and in many respects they resemble the Vascular Crypto- 

 gams, forming an intermediate group between these two. 

 They are large plants, usually trees. In the Angiosperms, 

 the ovules, or " young seeds," are enclosed in a cavity, the 

 ovary, but in the Gymnosperms the ovules are freely ex- 

 posed, since the carpels if present are not closed up to form 

 ovary, style, and stigma. The flowers are always unisexual 

 and generally on the same plant, but sometimes on different 

 plants (Yew, Juniper, etc.). 



Scots Fine. The only native British Gymnosperms are 

 the Yew, the Juniper, and the Scots Pine (sometimes called 

 the Scots Fir, though the Firs are very different from the 

 Pines). The main external characters of this tree have 

 already been described ; see Arts. 180 and 377. 



The plant produces two kinds of branches and two kinds 

 of leaves. The ordinary branches, or " long-shoots," which 

 are produced annually in apparent circles, bear only scale 

 leaves. In the axil of each of these scales there arises a 

 dwarf shoot, which bears a number of scale leaves and a pair 

 of foliage leaves, or "needles" (Fig. 10). In some Pines 

 " needles " are produced in threes or fives instead of pairs. 



In the general arrangement of the tissues the stem of the 

 Pine resembles that of a Dicotyledon. A young twig, in its 

 first year of growth, shows a ring of bundles in cross section. 

 Between the bundles there are narrow medullary rays which 

 connect the pith with the cortex ; in the cortex there are 



