56 ADHESION. 



softer wood than the foi'mer, yet the branch of the 

 harder wooded tree was flattened, as if subjected to 

 great pressure.^ It is possible that some of the 

 cases similar to those spoken of by Columella, Virgil,^ 

 and other classical writers, may have originated in the 

 accidental admission of seeds inj:o the crevices of trees; 

 in time the seeds grew, and as they did so, the young 

 plants contracted an adhesion to the supporting tree. 

 Some of the instances recorded by classical writers 

 may be attributed to intentional or accidental fallacy, 

 as in the so-called " greffe des charlatans " of more 

 modern days. 



Adhesion of the roots of different species has been 

 effected artificially, as between the carrot and the beet 

 root, while Dr. Maclean succeeded in engrafting, on a 

 red beet, a scion of the white Silesian variety of the 

 same species. In all these cases, even in the most 

 successful grafts, the amount of adhesion is very slight ; 

 the union in no degree warrants the term fusion, it is 

 little but simple contact of similar tissues, while new 

 growing matter is formed all round the cut surfaces, 

 so that the latter become gradually imbedded in the 

 newly formed matter. 



Synophty or adhesion of the embryo. This often occurs 

 partially in the embryo plants of the common mistleto 

 (Viscum), but is not of common occurrence in other 

 plants, even in such cases as the orange (Citrus), the 

 Cycadeie, Cimijhw, &c., where there is frequently more 

 than one embryo in the seed. Alphonse De Candolle 

 has described and figured an instance of the kind in 

 Eiipliorh'ui heUoscopia, wherein two embryo plants were 

 completely grafted together throughout the whole length 



' An instance of this kind is cited in Dr. Robson's memoir of the late 

 Charles Waterton, from which it appears that two trees, a spruce fir 

 and an elm, were originally planted side by side, and had been annually 

 twisted round each other, so that they had in places grown one into 

 the other, with the result of stunting the growth of both trees, thus 

 illustrating, according to the opinion of the eccentric naturalist above 

 cited, the incongruous union of Church and State ! 



' See Daubeny, ' Lectures on Roman Husbandi-y,' p. 156. 



