40 Rhodora [Marcu 
season of active growth are in much the same condition as that in 
which they entered on their long winter rest. As active growth begins 
in the spring of the year, roots and leaves develop, (pl. 136, fig. 2) and 
the little plants soon become large enough to take their place in the 
colony and rapidly fill in any gaps that may have been caused by the 
death of older plants or by the creeping apart of their rhizomes. 
Up to the present time I have been unsuccessful in my search for pro- 
tocorms beyond the limits of the colonies, and yet within the colonies 
they are so numerous that the rhizomes, as they elongate, sometimes 
become entangled. 
From these observations I arrived at the conclusion that only those 
seeds which fall within a colony enjoy a bright prospect of successful 
germination. This is true because the mycorrhizal fungi are most 
likely to be present where mature plants are in abundance. Those 
seeds which drift away on air currents or are blown abroad by the 
wind and fall where there is no nidus of the necessary fungus, fail to 
germinate. Otherwise, how account for the colony forming tendency 
of the species and the peculiarities of distribution? 
The protocorms adhere to the roots of mature plants or nestle close 
to the rhizomes beneath the rosettes of leaves, and may be aptly 
compared in their appearance to small white spiders at the centre 
of miniature webs, the webs being the delicate, elongated hair-like 
structures (rhizoids) which radiate in every direction and serve as 
passage ways for the fungal hyphae from the interior of the proto- 
corm to the humus (pl. 136, figs. 1 & 3). 
My investigations indicate that protocorms are more frequent in 
close contact with some part of the mature plants than in the open 
spaces between the rhizomes. That this condition prevails is pretty 
well shown by the position in which young leafy plants are usually 
found, that is, in such close proximity to the rhizomes of older plants 
that they may readily be mistaken for young offshoots. In fact, 
before I was convinced of the correctness of my conclusions with 
regard to the nature and origin of young plants that had developed 
several leaves, I used to suspect that they were really offshoots and 
that in freeing them for study I had broken them away from the point 
of origin on mature rhizomes. 
It is worthy of note that many protocorms are quite free from 
direct contact with the surrounding humus. They may lie suspended 
