Page:The American Cyclopædia (1879) Volume XI.djvu/693

 MISTLETOE 675 ther ; for it is one of the most reasonable, safe, and well established rules, that no evidence from without a written contract shall be per- mitted to control or vary it. While parties are negotiating they may change their minds and vary their demands and concessions, and gen- erally do this to some extent. But when they have finally put their terms in writing, the law supposes that these are what they have con- cluded upon, and that they have chosen and used the very words which express their mean- ing ; and that whatever is not therein stated, although it may have previously passed be- tween them, has been purposely omitted be- cause it was not finally agreed to. It would therefore be manifestly unjust to permit evi- dence of any of these things to come forward and vary the written contract ; and hence the rule, which is concisely expressed in the Scotch law thus: " Writing cannot be cut down or taken away by the testimony of witnesses." But while evidence must not vary, it may ex- plain, the contract. Thus, in the most solemn deed, it may be necessary to explain the terms of the instrument, in order to show who the parties are, what the boundaries of land mean, or where it is situated. But it is a very differ- ent thing when one of the parties says that the deed contains a mistake; that the house or the field it conveys is not the house or field which it was intended to convey ; and on this ground demands to hold the house or field which, as he alleges, should have been given to him. And it may be regarded as the estab- lished rule concerning mistakes, that any mis- take in an instrument may be corrected by construction, if the instrument itself affords the means of correction ; but not, if it can be done only by going outside of the instrument. Courts of equity, however, have large powers to reform conveyances and contracts where by mistake in drafting them they are made to express a different intent from the one agreed upon. (See CHANCERY, and EQUITY.) MISTLETOE (Anglo-Saxon mistiltan, from mistl, different, and tan, twig, as the plant is unlike the tree upon which it grows), a parasi- tic evergreen shrub of the family loranthacece. The true European mistletoe is mscum album, the generic name being the Latin word for the plant as well as for bird lime. The family comprises about 30 genera of mostly tropical evergreen shrubs, all of which are parasitic, and some of which have showy flowers ; a de- scription of the less conspicuous mistletoe will give the general characters of the whole fam- ily. The genus mscum, besides the common European one, comprises a few Asiatic species. The mistletoe is succulent when young, but becomes woody when old; its branches are repeatedly forked, and form together dense tufts 1 to 2 ft. in diameter, and attached to the branches of the trees by the thickened base of its main stem ; the branches break readily at the distinct joints, at each of which is borne a pair of opposite, sessile, thickish leaves, which vary from narrowly oblong to obovate, but are always entire and obtuse ; the flowers are dioecious, nearly sessile in the forks of the branches; those in the male plant three to five together in a somewhat cup-shaped involucre, with short, thick, triangular petals, and the Mistletoe (Viscum album). same number of stamens, which are sessile in the centre of the petals, their anthers opening by several pores ; the female or pistillate plant has its flowers solitary, rarely two or three together, and consisting of four minute petals at the top of the ovary, which is one-celled, with a simple style, and in ripening forms a white, semi-transparent berry with a single seed, surrounded by an exceedingly viscid or glutinous pulp. The mistletoe extends from Sweden to the Mediterranean, and is very common in the southern and western coun- ties of England, where it grows upon a great variety of trees ; it especially affects the apple, and in the cider districts is very destructive to the trees, as when once established it continues to grow as long as there is any life in its host. It is supposed to be disseminated by birds which feed upon the berries, and that in their attempts to wipe the viscid pulp from their bills they attach the seeds to the bark of the branches. To establish the plant artificially, a small slit of the bark is raised with a knife and the seeds are placed beneath it ; this is done upon the under side of a branch to hide the seed from birds. Many experiments have been made upon the germination of this plant, and it is found that, in whatever position the seed may be placed, the radicle, which in ordinary plants tends directly downward, will be di- rected toward the surface to which the seeds are attached, without reference to gravitation, light, or any other influence. The radicle is frequently obliged to arch itself over to reach the bark, and when it comes in contact with this its end expands to form a disk which gives it a firm hold ; from this proceed roots which