830 



which unites the two artifically connected members, is called the "connecting 

 layer/' or, according to Goppert, "intermediary tissue." The scion is either 

 a single bud, which has been separated, together with a part of the adjacent 

 bark, or a piece of a twig with several buds. According to the cultural 

 purpose the scion can be inserted at the place of its removal, or at some 

 other place in the same individual or (most frequently) on some other indi- 

 vidual. In the first phase, only the effect of the injury; in the latter, in 

 addition the influence of the difference in character of the scion and the 

 stock will have to be considered. 



This process of improving the "stock" will have to be considered first 

 of all as a process of wound healing; the favoring, or arresting influence, 

 will have to be taken into account secondarily, due possibly to the mutual 

 interaction of the two artificially connected plant parts. 



Among the authors treating this subject thoroughly, Goppert^ should 

 be named first of all. He took up the subject especially through anatomical 

 studies. A year after the publication of Goppert's well illustrated work I 

 published a supplementary^ article, in part confirming it and in part correct- 

 ing it". Among the earlier physiologists, the statements of Hanstein^, of 

 de Candolle*, of Treviranus^ are especially worthy of consideration. 

 Thouin® made a systematic compilation of all the possible variations in the 

 process of grafting. He based his work on Duhame^, La Ouintinye^, 

 "Rozier®, Cabanis^" and the other horticultural writers and by means of 

 abundant bibliographical citations facilitated tremendously the study of the 

 history of the art of grafting. 



Of the various forms of grafting w^hich Thouin describes in his book 

 under separate names and usually illustrated, only a very few have found a 

 general acceptance. All the forms in use at present will from a pathological 

 point of view be best arranged in their respective values, according to the 

 degrees of injury w^hich the stock suffers and according to the greater or 

 lesser degree of ease with which the wounds can be healed. Under other- 

 wise similar circumstances, the success of the manipulation will be the more 

 certain the more rapidly the tissue of the scion forms a firm connection with 

 the stock and, since this connection is brought about by means of the newly 

 produced cicatrization tissue of the wound, the rapidity with which the 

 wound is closed becomes the standard, chiefly, if not exclusively, for judging 

 the value of the form of grafting. 



1 Goppert, iiher innere Vorg-ange bei dem Veredeln der BJiume und Strilucher. 

 Kassel 1874. 



2 Sorauer, Vorlaufige Notiz iiber Veredlung-. Bot. Zeit. 1875, p. 201. 



3 Hanstein, Dr. J., Das Reproduktionsvermog-en der Pflanzen in Bezug auf 

 ihre Vermehrung und Veredlung. Wiegandt's Volks-und Gartenkalendar 1865, 

 p. 190. 



4 De Candolle, Physiologie v6getale II. 



5 Treviranus, Physiologie der Gewachse 1838, 11, p. 647. 



6 Thouin, Monographic des Pfropfens. Berg's translation, 1824. 



7 Duhamcl, Physique des arbres 1758, II, p. 75. 



8 De la Quintinye, Le parfait jardinier. Paris 1695. 



9 Rozier, Cours complet d' Agriculture, Vol. V, p. 346. 

 10 Cabanis, Principes de la Greffe, p. 105. 



