1899] DISTURBING THE BALANCE OF NATURE 311 
trees were cleared, and at present the scales are being reared to 
preserve the lady-bugs in case of another outbreak.” In 1897, in 
Portugal, the experience of the United States was successfully repeated. 
From Dr. Blackford’s article we may take one other example: 
“Tn many of the rivers of Brazil a plant grows that is called the 
Water Hyacinth. It is very ornamental, and a few years ago a land- 
owner on the St. John’s River, in Florida, procured a small number 
for a pond on his estate. They increased rapidly and filled up the 
pond, whereupon the owner had them gathered up and thrown into 
the river. The experiment was unfortunate. Free from natural - 
enemies, the hyacinths have flourished, so that on many streams 
navigation is practically impossible. From shore to shore there 
spreads an impenetrable sheet of vegetation that entangles paddles, 
oars, or propellers, and arrests all manner of refuse that should go to 
the sea. From time to time bodies of this growth become detached 
and drift down until salt water is reached, when the plants die and 
are cast ashore in putrescent heaps. A natural enemy has been 
sought, but as yet no appreciable result has been accomplished. In 
Brazil a small red spider lives on the hyacinths, and is said to be 
injurious to it. This spider has been introduced into Florida, but no 
effect has been perceived.” 
In conclusion, the theoretical interest of these cases is all very 
well, but “things are in the saddle,” and practical considerations force 
themselves upon us. Therefore we have pleasure in quoting the last 
paragraph of Mr. Palmer’s article. “Congress should take steps 
promptly to protect Hawaii and Puerto Rico against further intro-. 
duction of noxious species, and to prevent the mongoose from being 
brought into the United States. The introduction of exotic mammals 
and birds should be restricted by law, and should be under the control 
of the U.S. Department of Agriculture. The wild rabbit, the mon- 
goose, the flying foxes, and the mina of the Old World, should be 
rigidly excluded; and species of doubtful value, such as the starling, 
skylark, kohlmeise, and blackbird, should be imported with the greatest 
care, and only in places where they can be controlled in case they 
prove injurious.” 
Notes on American Mammals. 
Mr. D. G. ELtiot, so well known from his magnificent illustrated 
monographs of various groups of animals, as well as from his less pre- 
tentious handbooks of North American game and water birds, has 
recently turned his attention to faunistic work. The results of his 
labours have been presented to the public in the “ Publications of the 
Field Columbian Museum,” and comprise the mammalian fauna of the 
Olympic mountains, notes on certain reptiles and batrachians from the 
