MANtJAI, OF NATURB STUDY. 1^5 



not exactly in the same way. There are many 

 of these spores in one single spore-sac and the spore- 

 sacs are so numerous and small that you ean scarce- 

 ly count the number upon a single frond. When 

 the sac bursts the air is always dry and considera- 

 ble breeze stirring. Under such conditions, what is 

 done with the spores? These spores, of course, 

 take the direction of the wind and are sometimes 

 carried great distances, falling upon the ground, 

 here and there, all along the way. 



If all ground were good for the growth of ferns, 

 the spores from a single plant would soon populate 

 the entire globe with ferns; but all ground is not 

 good for ferns. These plants are a little particular 

 about the sort of ground they grow in. The soil 

 must be damp and shady — ^not too wet, but damp 

 or moist. Around old, rotten logs or stumps these 

 plants will grow very luxuriantly, if the soil is 

 damp and shady. These spores, then, when they 

 find lodgment in these damp places, gradually de- 

 velop into very small discs or flattened leaves which 

 spread out upon the damp ground. Bach little flat 

 leaf, oxprothallium^ as the botanist calls it, sends into 

 the ground many very fine and delicate root-hairs. 

 As soon as the prothallium becomes thoroughly fixed 

 by its root-hairs, so as to obtain nourishment for 

 itself and the young plantlet which it is about to 

 give rise to, it develops on the under-surface, 



