FERNS AND THEIR RELATIVES 



scale is brown and shrivelled, because the little upright 

 leaves have gone to work and can do without it. In a 

 month or so the little plant will begin to look quite 

 like a young fern; there will be a minute underground 

 stem, a number of branching roots, and new leaves that 

 look more and more like grown up fern leaves. But it will 

 be several years before the plant will be fully grown and 

 bears spores; then it may last for many years, that is, the 

 leaves each spring will make more food than they need for 

 themselves and their spores, and will send it down to the 

 underground stem for the benefit of the next season 's leaves. 

 Examine the underground stem of the larger ferns you have 

 collected, and see if you do not find traces of the leaves 

 of other years. 



The little fern growing from the spore in Fig. 30, is a 

 golden-back fern, and one a year or two older is pictured 

 in Fig. 27, No. 3. Everybody in California knows and 

 loves this fern. The golden dust on the under side of the 

 leaf, is so abundant that it leaves a beautiful golden imprint 

 if you press a leaf against a dark dress. This powder is 

 really a sort of wax, similar to the bloom on some leaves 

 and fruits. Perhaps you can guess one of its uses. You 

 know how quickly ferns wither when you pick them. This 

 is because the leaf cells have thin walls that give off moisture 

 readily. If these cells had thick walls the water current 

 that carries raw material to the leaves would move too 

 slowly, for ferns grow in shaded places and, in California, 

 do much of their food-making during the winter. But the 

 wax-like coating on the underside of the leaves protects 

 the layer of cells against evaporation; so when hot, dry 

 days come, you will see golden-back leaves curl up, leaving 

 only the under surface exposed; if the dry weather does 

 not last too long, the leaves will revive with moisture, but 

 unless these ferns grow in very sheltered places, they die 

 down to the ground before the dry season is over. 



75 



