October, 19*1.] THE ORCHID REVIEW. 
SEED DISPERSAL IN RELATION TO COLONY FORMATION 
IN GOODYERA PUBESCENS. 
By Oakes Ames, F.L.S., Director of the Botanic Garden of Harvard University. 
HE reference on page 40 of the current volume of the Orchid Review to 
the dispersal of Orchid seeds may well be amplified by observations I 
have made in connection with mycorrhiza of New England species. 
In efforts to ascertain the earliest stage of development, under natural 
conditions, at which the mycorrhizal fungus penetrates the embryo of our 
native Orchids, studies were undertaken of several species that seemed 
likely to furnish material in abundance. Goodyera pubescens R. Br. was 
finally selected for intensive observation through a period of twelve months. 
Goodyera pubescens in its native haunts forms attractive colonies in which 
the dark green leaves with whitish veins often make mats over areas several 
square metres in extent on the woodland floor. The racemes of white 
globular flowers are produced in late July and early August. The capsules 
dehisce and shed their seed before the winter months come on. 
The colonies or patches of this species are usually widely scattered. If 
single plants occur they are rare. As the creeping rhizomes would soon 
create open spaces in a colony and would gradually give rise to an ever- 
widening circle as the plants crept toward the periphery of the inhabited 
area, my interest in the life history of the species was awakened, and an 
attempt to explain the cause, persistence and characteristics of the colonies- 
was instituted. That the formation of the colonies is in part due to seed 
dispersal my observations soon proved. 
I discovered that the colonies are constantly replenished by seedlings,, 
and that with rare exceptions only those seeds are likely to experience 
conditions favourable to germination that fall on the humus among mature 
plants ; in other words, that find lodgment within the confines of a colony. 
This is to be explained on the assumption that seeds which drift away on- 
the wind and fall where the ground is sterile, as to the necessary 
mycorrhizal fungus, fail to germinate unless they have been infected before 
dissemination. The seeds that drop within the colonies soon nestle close 
to the rhizomes of mature plants, where they may, at the proper time,, 
presumably in June or July of the year following dissemination, enter into 
partnership with a fungus which is present and supposedly necessary to 
stimulate germination. Careful observations revealed young plants in 
different stages of development within the colonies, close to mature plants,, 
the smallest ones being without leaves, of a whitish colour, and apparently 
devoid of chlorophyll. At first glance the more advanced seedlings might 
readily be mistaken for new growths from established rhizomes. The next 
