148 - General Notes. [ February, 
ing their prosperity. Leaving out any of these, he is like one 
who undertakes to make out the construction of a watch, but 
overlooks one wheel; and by the time he has studied all these 
sufficiently, he will find that he has run through the whole com- 
plicated mechanism of the aquatic life of the locality, both animal 
and vegetable, of which his species forms but a single element, 
* * * ¥* “T cannot too strongly emphasize the fact frequently 
illustrated, I venture to hope, by the papers of this series—that a 
comprehensive survey of our entire natural history is absolutely 
essential to a good working knowledge of those parts of it which 
chiefly attract popular attention—that is, its edible fishes, its in- 
jurious and beneficial insects, and its parasitic plants. Such a 
survey, however, should not stop with a study of the dead forms 
of nature, ending in mere lists and descriptions. To have an 
applicable value, it must treat the life of the region as an organic 
unit, must study it 2” action, and direct principal attention to the 
laws of its activity.” 
Prof. Forbes believes, from results so far obtained, that it will 
prove to be a rule “ that a fish makes scarcely more than a mechan- 
ical selection from the articles of food accessible to it, taking 
almost indifferently whatever edible things the water contains 
which its habitual range and its peculiar alimentary apparatus 
enable it to appropriate, and eating of these in about the ratio of 
their relative abundance and the ease with which they can be ap- 
propriated at any time and place. If this is so, knowing the 
structure of a fish and the contents of a body of water, we shall 
be able to tell, @ priori, what the fish will eat if placed 
therein.” 
Insect ENEMIES OF THE Rice Prant.—In the October number 
of the American Entomologist (Vol. 1, p. 253), we published an 
interesting communication from Mr. John Screven, of Savannah, 
Ga., addressed to Dr. J. L. LeConte, regarding insects injurious 
to the rice plant. We then referred the Scarabzid larva (or 
“‘orub”) which feeds upon the roots provisionally to the genus 
Ligyrus, being led to this conclusion by the circumstance that a 
species of this genus (L. rugiceps Lec.) attacks, in a similar way, 
the roots of sugar cane in the south, and that another species ( L. 
relictus Say,) which is common farther north, has been observed 
feeding on the roots of wild rice in the marshes bordering Lake 
Erie. Meanwhile Mr. Screven kindly sent us specimens of the 
perfect insect, which proves to be a closely related form, Chalepus 
trachypygus Burm. This beetle occurs through the whole extent 
of the Southern States, and is very common along the edges of 
the swamps, in the pine barrens and in similar moist grassy places, 
feeding both in the larva and imago states on the roots of 
grasses. 
Of the second species attacking the roots of rice, the “ maggot” 
of Mr. Screven (see Am. Ent. i. p, 262-3), no perfect insects 
