216 THE FARMER AT HOME. 



have remained for centuries, as frogs and toads in solid rocks, are 

 examples of continued hybernation, produced by being placed in a 

 position where the temperament and the confined state adopted at the 

 commencement of the hybernation, is continued by causes afterwards 

 superinduced. Thus the bats enclosed in the old mine, at Cheshire, 

 (Conn.,) by a slide from, the mountain, while in a state of hyberna- 

 tion, remained in that state for more than a quarter of a century, and 

 were so found at the reopening of the mine. Thus toads hybernating 

 in swamps, if covered, while in that state, to a depth which would 

 prevent the usual effects arising from the changes of the seasons, would 

 remain in that position, and the subsequent conversion of the covering 

 matter into stone, would enclose them forever in the rocky mass. It 

 is to this indurating process that we must ascribe the wonderful pre- 

 servation and continued vitality of those reptiles which are found in 

 the sand stones of the transition series. 



The condition of plants, too, during our winters, in which the sap 

 ceases to circulate, or circulates but to a limited extent, and in a lan- 

 guid manner, is a species of hybernation. It is a rest of the plant, a 

 cessation of its functions, growth ceases, and what may be called a 

 sleep of the plant ensues. Other causes may produce this rest of 

 plants. Numerous instances have occurred in which a second blos- 

 soming has taken place, and the flowers of the first of October have 

 vied with those of the first of May or June. This reviving of the 

 plant has been noticed in the apple, plum, and pear. It is unquestion- 

 ably to be attributed to the check which the extreme hot and dry 

 weather gave to the trees, and which produced on them an effect 

 similar to that of the hybernation of tropical plants. The functions 

 of the plant were for a time partially suspended ; heat had performed 

 the effect of cold ; the secretions of the plant, which prepare it for 

 blooming and reproduction, had been performed, and when rains suc- 

 ceeded the drowth, their blossoming in October as well as in May, was 

 Che natural result. 



HYBRIDS. When copulation takes place between different spe- 

 cies of animals, the progeny which in some cases is the result, is 

 termed a hybrid, as partaking of the qualities of both, yet distinct 

 irom either. Thus, a connection between the ass and the mare, pro- 

 duces the mule, and between the horse and the female ass, the hinny, 

 the two most common hybrids among animals. The hybrids among 

 animals do not have the power of reproduction, a proof that muling 

 is a violation of nature's laws, by which the races as distinct species 

 are governed. There has been in the highlands of Scotland a hybrid 

 between the stag and the mare, the first ever known. 



HYDROGEN. A constituent of water, and a rare gas, sixteen 

 times lighter than atmospheric air, and on that account used to fill 

 balloons. But its most important function is that of absorbing oxygen 

 from surrounding parts, when excited by any accession of heat or undue 



