IN support of the views expressed in Mr. D. Morris's interesting article on the above subject (NATURE, March 15, p. 466), I beg to be allowed to state the following facts. In the Island of Porto Rico, the Panicum barbinode, called there “malojilla,” has been cultivated for many years in the low humid lands, and it is a current opinion among farmers that it is reproduced by means of the animals feeding on it. Some fruit-bearing trees and shrubs, which are a favourite food for the wild Columba leucocephala and Columba corensis—among them the Solanum stramonifolium, the Bucida Buceras, the wild coffee, Coffea occidentalis, the palm-tree, Oredoxa regia—appear in some mountains and regions where they were formerly unknown, and there is no doubt that they have sprung from fruits and seeds transported by these pigeons. The Anona muricata (soursop), the Anona reticulata (custard apple), the Carica papaya (papaw tree), whose hard seeds are sometimes uninjured by the processes of mastication and digestion, are also believed to be planted accidentally by birds, and sometimes by hogs, horses, and other Mammalia. They grow all about in pastures where these animals are fed. The statement made about the orange-tree in Jamaica also holds good for Porto Rico. Very few orange-trees were planted in the interior of the country, and the tree is now wild in all that zone by the agency of birds in great part. There is no doubt, as Mr. Morris says, that birds and cattle have been the means of distributing plants all over the island.