THE MISTLETOE. 
273 
the embryo swells up, and becomes supplied with a crown of 
crowded hairs. This structure is the adhesive disc common to 
the members of the Loranthaceae. The swelling continues until 
it takes a symmetrical oval form, on the surface of which are to 
be seen the upwardly directed projections. While the adhesive 
disc develops in size, the elongated connection between this and 
the seed gradually withers away. Up to this time, however, it has 
served as an absorbing organ, taking the food from the endos¬ 
perm and bringing it to the developing distal portion which, as 
pointed out, becomes swelled up into an oval mass, and now be¬ 
comes attached to the epidermis of the cactus host.” 
The disc-shaped organ mentioned above serves both as a hold- 
Fig. 55. Germination of Phrygilanthus aphyllus. (a) The seed is stuck 
to the epidermis of the cactus, and the embryo winds about the thorn until 
its radicle end, swelling up to the disc, again reaches the epidermis. ( b ) 
Longitudinal section through the lower part of an elongating embryo. 
The plasmatic contents of the cells is pictured only in the central meristem. 
After Reiche in Flora. 
fast and as a secreting organ for an enzyme which aids in the 
penetration of the host by the haustoria. Dr. Cannon describes 
the entrance of the parasite (Phoradendron villosum) into the 
host: “ The branches [of the ash] are provided with prominent 
lenticels and if one of these chances to be directly beneath a disc, 
the epidermal cells of the disc enter it, dissolving or pushing to 
one side, or both, the cells of the host, and at length find them¬ 
selves in the cortex. This is not a matter of solution entirely, 
since the host-cells at the side of the haustoria give evidence of 
