: 
1893.] Cell Union in Herbaceous Grafting. 293 
were often seen in direct contact with the woody cells of the 
tomato, thus giving opportunity for the transferrence of water 
from the one to the other. 
Naturally one would not expect union between plants of 
different orders, and the successful grafting of Zradescantia 
sebrina upon tomato and of geranium upon tomato wasa sur- 
prise. The union of tomato, a dicotyledonous plant, and 
tradescantia, a monocotyledonous plant, was particularly in- 
teresting and points to the fact that a similarity in the ar- 
rangement of the woody and other tissues is not essential in, 
grafting herbaceous plants. 
Opportunity is here taken to thank Dr. J. C. Arthur, of 
Purdue University, for his kind assistance in the preparation 
of this article, the work upon which it is based being done 
under his supervision. 
Botanical Laboratory of Eli Lilly & Co., Indianapolis, Ind. 
EXPLANATION oF Plates XXX AND XXXI. 
Te eestos used: /, /, line of union; G, geranium; 7, tomato; P, potato; 
ia. 
-—Fig 1, Long. sec. of T to 7; young cells formed in process 
: tT 46.75 
a Trans. sec. o yw, zone; ¢p, cp, cen- 
Ti 7. . * @' cortical parenchyma; m, young cells.—Fig. 3. T 
to T; w, w, w. zo ti r¢ f zw, ! shown at time of grafting.-— 
: y 
-. en. sec. 7’ to 7, showing position of w, w, after graft ha‘ healed. 
~Fig 6 i sec. Pto 7, through central parenchyma; %, ¢, young cells. 
HS Sanepe t 2, cambium tissue; 4, bast cells —Fig. _ 
gE - 
fr: 
Trans. sec. 
Pto 7 walls formerly occupying places of #.—Fig. 1 : 
tone growth of tissue and formance of young cells, 7,,7, pn 
Walls of ih 4, Y, young transverse walls dividing young cells; /, ¢, thick 
cells, 
. g, p cen 
., 2 Cutting the slip: 
4, ‘Tichome arising ip; 2, 
