442 CANNON: GERMINATION OF PHORADENDRON 
usually somewhat roughened and appear not to bear lenticels. 
Therefore the mistletoe seedling that would penetrate the mesquite 
branch must be able to make its way through the outer cork either 
by pressure or by dissolving the periderm, or entrance must be 
gained at some other point, as at the axillary buds. The latter 
solution of the problem has been made. 
Even in older mistletoe plants it frequently happens that one 
can identify their place of attachment as being axillary, and in the 
younger ones the host sometimes sends out leaves from the same 
FicureE 5. P. Californicum penetrat- Ficure 6, P. Californicum 
ing the cortex of the mesquite ; the branch- entering the cortex of the mes- 
ing of the haustorium, which frequently quite in the region of the axillary 
may be seen, is shown. bud. , mistletoe seedling ; sb, 
the scale bases. 
axillary buds. And I have seen branches of the mesquite on which 
as many as half-a-dozen successive buds bore mistletoes. 
The manner of infection is as follows: seedlings which are 
attached to the internodal portion of the branch secrete solvents, 
as the discoloration of the cork immediately under the discs of the 
haustoria show, but they do not effect the penetration ; such seed- 
lings, however, as are attached either to the buds, or to the branch 
but close to them, and whose hypocotyls reach the buds, are those 
which at length gain admission into the sub-cortical host-tissues. 
The hypocotyls are pushed between the bud-scales to their base, 
the discs are formed in that position, and the secreting cells are 
thus brought at once in contact with cellulose cell-walls. These 
are penetrated without difficulty and, as mentioned above, appa! 
ently without exerting any pressure on the host (see FIGURE 5). 
