11 
be tested as stocks for the litchi. It is probable also that stocks 
may be found which will increase the hardiness of the litchi and thus 
make it possible to cultivate it outside of the Tropics. Resistance 
to disease and insect attack also is to be considered, and in this con- 
nection it is worth while to mention the apparent immunity of the 
longan (Euphoria Ion go no or Dimocarpus longan) to the attacks of 
the erinose mite, 1 which is destructive to the foliage of the litchi if 
not held in control. While the Chinese have not used other species 
for stocks, in their inarching varietal preferences have been discovered. 
Mr. G. Weidman Groff states that the variety Loh Mai Chi is inarched 
generally upon the variety San Chi about Canton. 2 
Experiments in grafting and budding the litchi on the longan have 
received some attention at this station. A method of bark grafting 
has proved thus far successful as a means of uniting these two species, 
now usually classified as of different genera. This has been used so 
far only in top-working the longan trees. The method consists in 
cutting off branches from 1 to 2 inches in diameter and immediately 
inserting in these small scions of mature wood from the desired 
variety of litchi, making incisions in the bark, beginning at the top 
of the cut in the stump and running down 3 or 4 inches. This 
process is illustrated in Plate III, figure 1. The wound is smeared 
with grafting wax, while the scion and top of the stock are covered 
with a heavy paraffined paper bag. The bag is tied about the branch 
to prevent excessive transpiration, as this would destroy the scion 
before it could become united to the stock. After about three weeks 
this may be removed, as it has been found that the scion united with 
the stock by that time. 
Repeated experiments with this method have shown that there is 
no great difficulty in securing a union of the litchi with the longan 
(PI. IV, fig. 1). A noteworthy influence of the stock on the scion 
should be mentioned here. The growth produced is very much more 
rapid than that of the litchi on its own roots, and in some cases the 
character of the foliage appears to undergo a change. It is, of 
course, too early in these experiments to know anything about hardi- 
ness, resistance to disease, kind of fruits, or many other important 
features. 3 
The budding of the litchi on the longan has been accomplished in 
Hawaii, but this method is not so successful as that of grafting 
described above. 
1 Vide, \>. 17. 
* U. S. Dept. Agr., Bur. Plant Indus., Plant Immigrants No. 111-112 (1916), p. 908. 
3 Since the above was written, attention has been called to repeated failures to make effective and 
permanent unions between these two genera where this work has been tried :n Washington, D. C, and 
in Florida. Unions are reported to have been made but they have not been permanent. This is not an 
uncommon result when grafting is attempted between widely different plants. At this time (Mar. :*, 
1917), the Hawaii Experiment Station plants are in a flourishing conuition, this being thirteen months 
after the setting of the scions. None has been lost since the first few weeks, when two failed. It is, 
however, too soon to know whether these unions will be permanent. 
