NATURAL GRAFTS. aT) 
blue, while some produced tubers partly white and 
partly blue. 
Adhesion of the axes of plants belonging to different species 
is a more singular occurrence than the former, and is 
of some interest as connected with the operation of 
grafting. As a general rule horticulturists are of 
opinion, and their opinion is borne out by facts, that 
the operation of grafting, to be successful, must be 
practised on plants of close botanical affinity. On the 
other hand, it is equally true that some plants very 
closely allied cannot be propagated in this manner. 
Contact between the younger growing tissues 1s essen- 
tial to successful grafting as practised by the gardener, 
and is probably quite as necessary in those cases where 
the process takes place naturally. Although there is 
little doubt but that some of the recorded instances of 
natural or artificial grafting of plants of distant bo- 
tanical affinities are untrustworthy, yet the instances 
of adhesion between widely different plants are too 
numerous and too well attested to allow of doubt. 
Moreover, when parasitical plants are considered, such 
as the Orobanches, the Cuscutas, and specially the 
mistleto (Viscum), which may be found growing on 
plants of very varied botanical relationship, the occur- 
rence of occasional adhesion between plants of distant 
affinity is not so much to be wondered at. Union be- 
tween the haulms of wheat and rye, and other grasses, 
has been recorded.’ Moquin-Tandon* relates a case 
wherein, by accident, a branch of a species of Sophora 
passed through the fork, made by two diverging 
branches of an elder (Sambucus), growing in the 
Jardin des Plantes of Toulouse. The branch of the 
Sophora contracted a firm adhesion to the elder, and 
what is remarkable is that, although the latter has much 
' Senebier, ‘ Phys. Végét.,’ t. iv, p. 426. The same author also cites 
Romer as having found two plants of Ranunculus, from the stem of 
which emerged a daisy. As itis not an uncommon practice to stick a daisy 
on a buttercup, it is to be hoped no hoax was played off on M. Romer. 
? «El. Ter. Veg.,’ p. 289. 
