1S78.] 



AN/ ) JfOR TICUL TURIS T. 



117 



Spkcific Heat in Trees.— The Gardener's ble matter sufficient to prevent the freezing of 

 Chronicle gives the following sketch of some what it has retained, while the evergreen is all 

 proceedinos in Germany : the Winter long exposed to evaporating influ- 



-Dr. Bolle recentlv cmnnmicated to the ences which dry out the jnoisture to an extent 

 Horticultural Society of Berlin some interesting utterly unknown to the moist atmosphere of 

 particulars of the relative hardiness of different Europe, wher ' people say deciduous trees are 

 ti-ees in Germany. Species of Carya which suc- 

 ceed admirably in the Central States of North 

 America suffer from May frosts. Pterocarya 

 Caucasica survives, but only on dry soil. The 

 Cedar of Lebanon, although it ascends to the 

 snow region in its native country, is not perfect- 

 ly hardy, whereas the Deciduous Cypress, Taxo- 

 dium distichum, is not injured. The latter in- 

 habits the Southern States of Northern America, 



" at rest " in Winter, as compared wiih ever- 

 greens. It is hard to tell what is really meant. 



INTERKAL Heat OF PLANTS.— In France 

 Ihey are troubled much by May frosts in the 

 vineyards. An article has recently appeared 

 in the Annales'des Sciences Naturelles showing 

 that two grape-growers sow the vineyard with 

 rape seed in October, which by May is several 

 feet high. The heat given otf by this mass of 

 nnd is one of the few instances of plants which \ jjying vegetation is said to be sufficient to raise 

 will bear a climate colder than that of the I ^-^^ temperature a few degrees, and thus protect 

 country in which they now exist in a wild state, j ^j-^g yjnes from frost. It may also have the 

 In his useful Book of Evergreens Josiah Hoopes ; effect of shading the ground, and prevent sun 

 says, 'The Deciduous Cypress, although strictly ^yarming, thus keeping back growth a little, 

 a, Southern tree, thrives admirablv in the climate 



of the Middle States. Its most northern natural Slitting the Bark of Trees.-Au impres- 

 limits are the Cvpress swamps of Marvland, and sioti prevails in some hitelligent quarters that 

 the extreme southern part of Delaware.- the bark of trees never becomes mdurated, or 



hide-bound," in technical language, unless 



Throughout every portion of the Southern States 

 this tree is found in the low miasmatic swamps \ something is wrong with the roots. It often 

 and occasionally verv plentifullv, especially ' does result from root injury ; but there are many 

 alonir the borders of the rivers and larger | causes, quite independent of this. Nature her- 

 ^streains. Indeed, in the Gulf States these Cy- ; self provides for the rupture of bai-k m the 

 press swamps cover thousands of acres, and form atimi ot suber cells, 

 along the Mississippi river particularly they ex- 

 tend for hundreds of miles.' Like the Arbor- 

 vitfe this tree sheds not only its leaves but also 

 its ultimate branchlets, which may possibly ex- 

 plain its hardiness. The Mexican variety, of 

 which a tree girthing 100 feet is said to exist at 

 •Chapultepec, is tender. Dr. Bolle thinks these 

 peculiarities in the constitution of plants are 

 governed by the distribution of heat in the dif- 

 ferent seasons of the year. One of the mem- 



It is by their action 

 that " rifts " take place. Every kind of tree has 

 its own species of suber cells engaged in this 

 work, and hence the rifts in no two species are 

 exactly alike. The effect of these growths has 

 been checked in "hide-bound" trees, though 

 often every other part of the tree is in a normal 

 and healthy condition. In these cases the knife 

 aids very acceptably in slitting such bark, the 

 work the suber cells failed to perform. 



Ripening of Fruits.— Prof. Albert Prescott 

 bers present observed that deciduous shrubs , contributes to the Popular Science Monthly a 

 generally withstand frost better than evergreens, ! paper on the chemistry of fruit ripening. The 

 because they are at i-est in Winter, mentioning I sweetest fruits to the taste may not really have 

 as examples Magnolia glauca and Larix as much sugar as those which taste more sharply. 

 Ktempferi." Currants have G and gooseberries 7 per cent, of 



It has long been known here that deciduous sugar, while a peach and an apricot have little 

 trees are hardier, and evergreens more tender, over one per cent. The grape has over 14 per 

 in America than in Europe, as a general thing. ; cent. — more than any other fruit. It is gener- 

 Our hot, dry Summers enable the trees to get I ally supposed that sugar is made from starch in 

 rid of their surplus moistm-e ; and, as they have ' ripeidng, |)ut there are some fruits with sugar in 

 little evaporating surfaces during Winter, what \ which no trace of starch has ever been found, 

 they have they keep. They have no excess to j Moist heat favors the chemical process of fruit 

 freeze and rupture the cells, and have accumu- j ripening, just as unripe fruits are made mor3 

 lated heat enouijh and secreted non-congeala- ■ edible by boiling. 



