THE COMMON BRACKEN 83 



of the leaflets appear as brown streaks, and in walking through a 

 patch of bracken in autumn one gets covered with rusty powder. 

 If you scrape some of these brown bodies on to a piece of white 

 paper, or a moistened bit of glass, and examine them with a lens, 

 you may be able to see that each has a slender stalk. Cut off 

 a few " ripe " leaflets in autumn and lay them on a sheet of paper 

 for some time, or shake a leaf over the paper, which will be 

 covered with fine brown dust which has escaped from the stalked 

 bodies. The dust-particles are the spores, the stalked bodies the 

 spore-cases. It is easy to make a spore-case burst, by pressing 

 or by warming it on a glass slip ; the case gapes open and lets the 

 spores out. This naturally happens on a dry day, and the spores 

 fall to the ground, or, being very light, are carried away by the 

 wind. It is easy to see why the spore-cases are produced on the 

 lower side of the leaf ; if they were on the upper side the sun 

 might injure them, while rain would make the spores stick to- 

 gether so that they would fall out in a mass. As we shall see, the 

 spore-bearing plants have adaptations for ensuring proper dis- 

 persal of their spores, just as the flowering plants show devices 

 for scattering their seeds. 



Why do botanists give the name spores to what many people 

 call the " seeds " of ferns ? The best way to find out what the 

 spores are is to grow them and see what they give rise to. If 

 you have a microscope, you can tell at once on examining a fern 

 spore that it is not a seed. A seed contains a young plant, with 

 root and shoot, and usually a store of food (in cotyledons, or in 

 a special part called the endosperm), whereas a spore does not 

 contain a young plant, but is a single cell, so that it is an almost 

 infinitely simpler structure than a seed. 



What becomes of the spores after they are shed by the burst- 

 ing open of the spore-cases ? You might search the soil among 

 bracken plants for days without finding out, so the best plan 

 is to sow the spores yourself and keep them under observation 

 indoors. The spores of ferns should be collected by enclosing 

 a ripe leaf, or part of the leaf, bearing the spore-masses, in an 

 envelope on which you should write the name of the fern ; you 

 should have a few envelopes with you when on a botanical ex- 

 cursion. Get some flower-pots or shallow seed-pans, some lumps 



