26 
MacDougaL — Symbiotic Sap rophytism . 
that of Corallorhiza and Epipogium. Yellowish fungal clumps 
were found near the nuclei of the cells of the medio-cortex 
which he regarded as plasmodial : strands of protoplasm were 
seen extending between the nuclei of neighbouring cells, which 
he did not regard as hyphae. The examination given was 
preliminary, however, and it seems quite probable that the 
‘ strands ’ were hyphal structures similar to others recently 
described in mycorhiza. No facts were brought to light to 
show that the coralloid structures were pathological formations, 
and they were regarded as similar in general nature to the 
coralloid underground structures of Corallorhiza. Since they 
were small and not of invariable occurrence, Lundstrom was 
disposed to regard them as vestigial structures of no present 
use to the plant, but as indicating a phylogenetic relationship 
between this genus and Corallorhiza. This last conclusion 
does not seem well-founded in the light of the facts concerning 
Aplectrum stated on p. 20. The development of the stem- 
mycorhiza on old bulbs more or less nearly spent, points to the 
conclusion that here, as in Aplectrum , it is an effort to supple- 
ment the scanty supply of food available to the young plant 
by absorption of humous products. From the observations 
of the writer on specimens in the field from Michigan west- 
ward to Idaho, and Washington, it appears that the individuals 
grouped under this species show great extremes of variation in 
leaf- and flower-characters, although unfortunately the sub- 
terranean organs were not examined on the same specimens. 
Some systematists are disposed to divide it into two species on 
account of these variations which as yet are fairly continuous. 
It is to be seen therefore that the genus Calypso is in a state 
of very unstable equilibrium, and it seems entirely justifiable 
to ascribe this in part to the fact that young plants may be 
formed from old bulbs by means of coralloid offsets, instead 
of by normal non-absorbing organs. The influence of such 
mycorhizal structures would of course be quickly apparent in 
leaves and flowers 1 . 
1 Since this article was sent to press, the writer has re-discovered the coralloid 
formation. 
