25 
Mac Doug a l. — Symbiotic Saprophytism . 
amount of complex substances can be acquired by mycorhizal 
arrangement in this species, however, because of the weak 
development of this adaptation. 
Calypso bulbosa ( Calypso borealis, Salisb.). 
The underground portion of this plant consists of a small 
ovoid bulb bearing a small number of short simple roots, 
which are generally coated with humus though the habitat of 
the species shows the greatest variation. The vegetative 
reproduction of the plant is effected by the formation of 
a short offset, the apex of which becomes converted into the 
bulb of a young plant after the manner of Aplectrum. The 
specimens examined showed the presence of mycorhizal Fungi 
in the cortex of the roots, forming roughened vesicles closely 
appressed to the hyperchromatic nuclei. Hyphae were seen 
extending outward through the root-hairs. The conducting- 
tissues are but weakly developed, and the endodermis could 
not be clearly distinguished. 
Spontaneous variations. Although this species is credited 
with ‘ coralloid roots ’ in many systematic descriptions, yet no 
structures of this character have been found on specimens 
examined by the writer. Their existence seems well-authen- 
ticated however. The following note in the Botanical Gazette 
records their presence in America (28) : 6 Calypso borealis has 
not usually been credited with the possession of coralline 
roots. These were pointed out to Dr. Gray several years ago 
by Mr. Hitchings, of Boston, and the fact was called to mind 
lately by seeing such roots on fine specimens of this beautiful 
Orchid brought to the Botanic Garden at Cambridge from 
the White Mountains by Dr. Goodale.’ A. N. Lundstrom 
observed the plant through a period of ten years beginning in 
1862 : ‘ bei Langviken unfern Pitea ’ in Sweden (28). He 
found coralloid appendages on large numbers of old bulbs 
from which flower-stalks had sprung in previous years. These 
structures were found to be rhizomes densely branching in 
one plane, with rudimentary leaves of conical form arranged 
in a | order. The general appearance was very similar to 
