30 MacDougal. — Symbiotic Saprophytism. 
would contain the humous products, and be available for 
the fungal symbiont. This arrangement would obviate the 
necessity for the external development of the hyphae. The 
presence of mycorhizal Fungi in epiphytic roots suggests 
a similar use of the velamen in them. It would be impossible 
for the hyphae in these organs to maintain an external form 
of sufficient size to be of any appreciable use in absorption. 
When the dripping water is drawn into the velamen, however, 
the organic compounds contained are readily taken up, and in 
turn transmitted to the higher symbiont. The velamen then 
is an absorbing device in some instances, of especial value in 
mycorhizal forms. 
Sarracenia purpurea, L. 
Sarracenia , as an example of the carnivorous plants, was 
examined to ascertain whether a second method of sapro- 
phytism might also occur. The simply branching-roots are 
yellowish brown in colour, due to the presence of globules of 
colouring-matter in the exoderm, which is modified in many 
instances by the network of hyphae ramifying over the 
surface. These hyphae penetrate the epidermis in many 
places, and pass through the exoderm by way of certain cells 
free from colouring- matter, forming clumps of coils near the 
nuclei of the cortical elements. The distribution is most 
unequal, and the Fungus must be considered as a parasite, 
though it is not present in sufficient abundance to work 
material harm to the host. Such semi-aquatic species as 
Sarracenia are generally without mycorhiza : moreover, 
mycorhiza has not been detected in any of the pitchered 
carnivorous plants. The same is true of the Droseraceae. 
The acquisition of a certain amount of organic food-material 
by the carnivorous habit would probably prevent any adapta- 
tion of the roots for a similar purpose. 
Coptis trifolia (L.), Salisb. 
The long slender creeping stems of Coptis give rise to 
a few thin unbranched roots which penetrate the loose sub- 
stratum of decaying moss or humus in every direction. The 
