Russia witness the formation of numerous miniature canons, or ovraghi (deep ravines), the summits of which rapidly advance and ramify in the loose surface deposits.
From the northern end it is connected (I) with the polar sea northward by Smith Sound, prolonged by Kane Basin and Kennedy and Robeson Channels; (2) with the straits which ramify through the archipelago to the north-west by narrow channels at the head of Jones Sound, from which O.
As the buds develop the canal system becomes much extended, and calcareous tissue is deposited between the network of canals, the confluent edgezones of mother zooid and bud forming a coenosarc. As the process continues a number of calicles are formed, imbedded in a spongy tissue in which the canals ramify, and it is impossible to say where the theca of one corallite ends and that of another begins.
To the base of the stem are attached a number of branched cell-threads (rhizoids) which ramify in the soil, fixing the plant and absorbing water from soil.
The other type is called endctropic. The fungal filaments either penetrate the epidermis of the root, or enter it from the stem and ramify in the interior.