THE WONDERS OF VEGETATION. 245 



the number of seeds that can be gathered from an elm 

 according to him this tree furnishes every year more 

 than 520,000 ! 



It is evident that if all these seeds attained devel- 

 opment, it would require only a few generations for 

 these plants to cover the whole surface of the globe. 

 "But a multitude of causes retard this threatened inva- 

 sion. 



The fecundity of some mushrooms is still more ex- 

 traordinary. Fries has counted more than 10,000,000 

 spores upon a single individual of the Reticularia 

 Maxima. Other plants of the same family produce 

 a still greater number of possible successors indeed 

 the abundance is so extraordinary that all the powers 

 of the human intellect do not enable us to compute 

 their actual number. 



The majestic Arancaria of Patagonia bears at the 

 tips of its branches 20 or 30 fruits of one tree, and 

 each fruit contains about 300 kernels. Except by 

 scattered families of the savage natives who subsist 

 mainly on these fruits, the country is almost untrod- 

 den by man and left to itself, and hence the arancaria 

 has formed, according to the interesting account of 

 Dr. Peoppig, immense forests extending north and 

 south for over 800 miles. 



On the other hand, such is the fecundity of some 

 of the gigantic Ly coper don gigantium, that micro- 

 scopic spores must be counted by millions of thou- 

 sands of millions. But although they are invisible to 

 the eye, each of these spores can produce a mush- 

 room which, in one night, may attain the size of a 



