119 



THE COMMUNICABILITY OF VARIEGATION. 



Ill a paper in the Bull, de I'Acad, Royale de Belgique (2nd series, 

 vol. xxviii. p. 434), M. Edouard Morren gives the result of some ex- 

 periments on this subject. In common with many other botanists, he 

 regards variegation as a result of a diseased condition of the individual 

 plant, and not usually, though sometimes, hereditary. 



In experiments made with a variegated Abutilon {J. Thompsoni), 

 it was found that when this was grafted on other species and varieties 

 of the same genus, the abnormal or morbid state was communicated 

 to the stock, not only the new shoots bearing variegated leaves, but 

 even the old leaves taking on the same condition. This happens 

 if the graft dies ; but Avhat is more remarkable, M. Morren found 

 that the insertion of even the petiole of a variegated leaf beneath the 

 bark was sufficient to communicate the change as by a sort of inocula- 

 tion. Further, tliis morbid state is capable of indefinite transmission 

 by contagion, the power of inoculation being as great in the communi- 

 cated cases as in the original. Some species, however, have a greater 

 susceptibility than others. 



These facts have been partially known to botanists for some time, 

 but have not before been so clearly demonstrated. (See also report 

 of Meeting of Eoyal Horticultural Society for March 2nd, in this 

 Joiu'nal.) 



CAOUTCHOUC. 



At a recent meeting of the Society of Arts, Mr. James Collins read 

 a paper on " India-rubber, its History, Commerce, and Supply," which 

 naturally involved the question whether Caoutchouc could be cultivated 

 with profit in any of our tropical possessions. The interest generally 

 felt in the subject was evident from the crowded state of the rooms, 

 and the attentive ear the audience lent to the paper, and the discussion 

 that followed it. Mr. Collins advocated the acclimatization of the 

 different species of the genus Ilevea (Siphonia) in the East Indies, 

 because this was known to yield tlie best Caoutchouc. But it might 

 be desirable, if any steps be taken in that direction, — will our colonial 

 gardens take the hint ? — to make not only a trial with the species in- 

 dicated, but also with all other plants known to yield that substance. 



