818 Means of Plant Dispersion, [ August, : 
around the tree on which they grow. They do not fall vertically 
as when the air is still, but are deflected from this course. All 
who remember their childhood experience in gathering nuts, will 
confirm this. They were not all found beneath the particular 
tree that bore them. In this way the heaviest of the forest fruits, 
like those of the butternut, walnut, hickory, chestnut, beech and 
oak, are quite extensively scattered. 
Plants are also blown about as a whole or in bulk, or their 
fruiting branches are thus blown. This is not uncommon with, 
grasses having capillary panicles. In this way species of Panicum 
(witch-grass) and Eragrostis are sent whirling over the fields in 
autumn,-and are often seen piled against a fence, or the windward 
side of any obstacle by which they have been stopped. The 
same is also true of many other plants. Some of our common 
weeds are dispersed in this way. One example is in point. I have 
often watched with interest the movements of a weed abundant 
in gardens and cultivated fields, Amarantus albus. It is rightly 
named in some localities the zumble-weed. The diameter of a 
well-grown specimen is rather more than its height, the stems 
spreading in all directions from the short tap root. Soon turning 
upward at the ends, they make a bushy weed of a roundish form. 
When ripe and dry the constant tugging of the wind tears it from 
the soil and sends it rolling and bounding across the fields, much 
like a hat blown from the head. This constant jarring threshes 
out the seed that may have resisted gentler treatment, and sows 
it broadcast over the fields to annoy the farmer the coming yeate 
They are sometimes piled fence high in some of the large fields 
of prairie farms, to be blown away again in the opposite direction 
when the wind changes and dislodges them from their place of 
temporary rest. 
II. The second group of adaptations depends for its efficiency : ' 
on the agency of water. The limits of this paper will not eae 
mit the enumeration of the various plants that may, in different ; 
degrees, be aided in this way. If the germ is sufficiently pe ‘ n 
tected from injury while in the water, from germination wi ee 
destruction before reaching a place suitable for growth, this meas : 
of transfer may be available in a large number of cases. It m 
evident that islands have in this manner, and by the aid of wie : 
and animals, often or even mainly obtained their species of plas. 
usually like those of adjacent shores. The similarity of GE 
