2 2 MacDougal. — Symbiotic Saprophytism. 
of Vanilla planifolia , due to the presence of a mycorhizal 
Fungus, was noted by Cavara, but no division was found (4). 
Dangeard and Armand described variations of the structure 
of the nucleus in Ophrys in which a general similarity to 
the reactions of Peramium was noted (6), and with the above 
observation constitute the only known instances of the frag- 
mentation of the nucleus due to the action of a symbiotic 
Fungus. In some instances the presence of the Fungus 
causes hypertrophy of the nucleus, accompanied by cell- 
multiplication. The inner cortex of the root is rich in 
starch. The endodermis could not be made out clearly. 
The irregularly arranged bundles show no marked reduction 
of the conducting-tissues. The hyphae of the infesting 
Fungus find their way a short distance into the tissues of the 
stem, and might pass quite easily to the bases of the roots 
at the nearest internodes, after the manner of Aplectrum , 
although no such behaviour came under observation. The 
beginning encroachment of the Fungus in the stem suggests 
the possibility that the species might easily pass into the 
category of plants furnished with stem-mycorhiza, losing the 
roots in the process. No experiments were made upon this 
point however. The upright oblong ovate leaves are plenti- 
fully provided with stomata on both the inferior and superior 
surfaces. The epidermal cells of the superior surface have 
strongly convex cuticularized outer walls. The chlorophyllous 
cells are globose or ovoid, and only in places is a palisade- 
layer evident. This species was examined by Wahrlich, but 
no details of structure are given beyond the fact that a 
mycorhizal Fungus was observed (41). Frank has figured the 
occurrence of the Fungus in the medio-cortex of the rhizome 
in a manner similar to that described above (9). The forma- 
tion of the hyphal clumps, or absorbing organs, is similar 
to that described by the writer. Frank does not, however, 
figure the fragmentation of the nucleus of the higher plant. 
It is to be noted that, in the plants examined as above, the 
occurrence of the Fungus in the rhizome was very sparing. 
It seems probable therefore that this plant may in some 
