— no— 
forms lank lax tufts; when disturbed the stems lie prostrate but growth is 
hardly arrested: by an exaggeration of the geniculate curve which is a feature 
of several species, the apiees recover a vertical position and re-establish 
themselves: in this case balls are not formed but vitality is preserved by a 
curvature of the stem. 
In large game birds may be found, I believe, an ever present and ever 
active agency for the periodical disturbance necessary. 
The activity of these birds may be gauged by an examination of a chest- 
nut grove in winter, when not a nut will be found ; hundreds of torn and 
empty husks will show that birds have fed there. The Leucobryum site at 
Aylmerton is under beech trees, and the fallen nuts give a direct reason for 
special attention from birds. 
It will not be out of place to refer to another roving moss mentioned by 
H. N. Dixon, in a paper on the moss flora of Northamptonshire, published 
in Journ. of Northamptonshire Nat. Hist. Soc. Vol. X. 1899. The author 
says: “A remarkable form of Porotrichum alopecurum Mitt, occurs in 
“ Weldon Quarries, which I have not found, or seen noticed, elsewhere. On 
“ a recent visit in the spring of 1898, the bottoms of some low depressions 
“ under trees were carpeted with globular mosses, which were found to con- 
“ sist of living ‘ balls ’ of this moss, entirely detached from the soil and with- 
“ out rootlets, and from two to four or five inches in diameter. The interior 
“of the ‘ balls’ consisted of the rigid, wiry stems proper to the species, which 
“had branched profusely in all directions, and so produced this peculiar 
“ form. The branches were extremely dense and numerous, many hundreds 
“ of secondary stems going to make up a single tuft or ‘ ball,’ and entirely 
“ hiding the central stem or stems. From this, as well as from the size of 
“ the tufts, it was clear that they must represent the growth of many months, 
“ probably of several years, and this without connection of any kind with the 
“soil or other matrix; so that the nutriment must have been obtained 
“entirely from atmospheric moisture; they were, however, perfectly fresh 
“ and vigorous. No doubt detached stems of this moss, the ordinary form of 
“which was growingin close proximity, has been carried at various times by 
“ the wind into the hollows, where the moisture of the air, together with the 
“natural vitality, apparently a marked character of the species, combined 
“ not only to resist decay, but even to promote growth, resulting in the very 
“ unusual phenomenon described.” 
In a later note Mr. Dixon records a similar growth of Porotrichum alope- 
curum in Ireland, reported by the Curator of the Fernery, Botanic Park, Bel- 
fast, who called it “ the rolling moss,” and described how it grew without roots 
and was blown about from place to place by the wind; he kept it as a curi- 
osity among his ferns. 
The unattached state of Leucobryum and Porotrichum bears no relation 
to the Wind Witches described by Kerner in Nat. Hist, of Plants, Vol. II, 
page 850. According to the author a number of herbaceous plants, inhabiting 
the Steppes of southern Russia, contract into flattened balls at maturity, and, 
becoming detached from the soil, are rolled along by gusts of wind. The 
