92 FLORA OF NEW PROVIDENCE AND ANDROS 
or feet? Their presence certainly seems very difficult to account 
for otherwise. Darwin says (Origin of Species, chapter thirteen) : 
“I have before mentioned that earth occasionally adheres in some 
quantity to the feet and beaks of birds. Wading birds which fre- 
quent the muddy edges of ponds if suddenly flushed would be the 
most likely to have muddy feet. Birds of this order wander more 
than those of any other, and they are occasionally found on the 
most remote and barren islands of the open ocean; they would 
not be likely to alight on the surface of the sea, so that any dirt on 
their feet would not be washed off, and when gaining the land 
they would be sure to fly to their natural fresh-water haunts, I 
do not believe that botanists are aware how charged the mud of 
ponds is with seeds. I have tried several little experiments but 
will here give only the most striking case: I took in February 
three tablespoonfuls of mud from three different points, beneath 
water on the edge of a little pond ; this mud when dried weighed 
only 634 ounces ; I kept it covered up in my study for six months, 
pulling up and counting each plant as it grew ; the plants were of 
many kinds and were altogether 537 in number and yet the viscid 
mud was all contained in a breakfast cup! Considering these 
facts, I think it would be an inexplicable circumstance if water 
birds did not transport the seeds of fresh-water plants to unstocked 
ponds and streams situated at very distant points." The plants 
mentioned above are not water plants, it is true, but they are com- 
mon in moist soil in the vicinity of ponds. 
The seeds of Pluchea may owe their transportation to the 
wind. But whatever the means of dissemination, the fact seems 
established that, although the bulk of the Bahama flora has prob- 
ably come from the south, there is a contingent, in the northern 
islands of the group at least, that owes its origin to the north. It 
is worthy of note in this connection that in a number of cases, 
when our plants were compared with large series of both Florida 
and Cuban specimens, they were found to resemble most closely 
the Florida specimens ; hence when species occur in both Cuba 
and Florida, it may well be that the Bahaman plants owe their 
origin to the latter. 
