The Sporing of the Fern 261 
early spring are generally hairy or scaly (Fig. 71), 
with brown transparent outgrowths which help to 
protect the tender frond from cold snaps and bitter 
winds. Later in the season hairs and chaffy scales 
may still be seen clinging to the fern-stalk and 
sometimes almost covering its lower portion. Under 
the microscope these scales are seen to consist each 
of a single layer of cells, with thickened brown 
walls, through which a mucilaginous or resinous 
liquid oozes. Gold and silver ferns have their 
under surfaces covered with hairs which exude re- 
sinous and waxy substances. 
But the trick of developing hairs is best under- 
stood by the tree-ferns, whose young leaves are 
completely buried in a brown mass of vegetable 
fur, sometimes utilized by robber man for stuffing 
matresses. 
By latter July most native ferns have attained 
maturity, and on the backs of the fronds, in many 
species, we can see dots and dashes of silver-green, 
dark-green, or brown. These are ‘‘sori,’’ and 
their general plan can be readily seen with a 
pocket-lens. 
Typically each sorus consists of a little scale or 
lid, covering a group, or perhaps two groups, of 
stalked sporangia, and each sporangium is a little 
