POWER OF MUSHROOMS. 207 



The Cucurbitaceoe are a small, but very useful order of the 

 vegetable kingdom, numbering about three hundred and fifty 

 species, which are chiefly natives of warm regions. The 

 most valuable species are the squash, the pumpkin, the 

 cucumber, the water-melon, the musk-melon and the gourd, 

 of all which there are numerous varieties. 



These plants are generally herbaceous, and trailing or 

 climbing by means of tendrils. Their stems, leaf-stalks, 

 tendrils and fruits are often hollow, and their tissues very 

 soft and succulent. 



The flowers are usually large, and either yellow or white, 

 and of two or three sorts on the same plant. The fruit is 

 commonly a pepo, the structure of which is familiar to all. 



The following considerations suggested the idea of experi- 

 menting with the mammoth squash : 



First. It is a well-known fact that beans, acorns and other 

 seeds often lift comparatively heavy masses of earth in forcing 

 their way up to the light in the process of germination. 



Second. We have all heard how common mushrooms have 

 displaced flagging- stones, many years since, in Basingstoke, 

 and, more recently, in Worcester, England. In the latter 

 case, only a few weeks ago, a gentleman noticing that a stone 

 in the walk near his residence had been disturbed, went for 

 the police, under the impression that burglars were preparing 

 some plot against him. Upon turning up the stone, which 

 weighed eighty pounds, the rogues were discovered in the 

 shape of three giant mushrooms. 



Third. Bricks and stones are often displaced by the growth 

 of the roots of shade-trees in streets. Cellar and other walls 

 are frequently injured in a similar way. 



Fourth. There is a common belief that the growing roots 

 of trees frequently rend asunder rocks on which they stand, 

 by penetrating and expanding within their crevices. 



Having never heard of any attempt to measure the expan- 

 sive force of a growing plant, we determined to experiment 

 in this direction. 



We were surprised, last year, in testing the pressure 

 exerted by the sap of various trees, to find that a black birch- 

 root detached from the tree, was able to force water to the 

 height of eighty-six feet. We were therefore somewhat pre- 



