INSECTIVOROUS PI AXIS. 45 



accomplished not, perhaps, yet awhile. Society may not yet require 

 them ; the world could not at present afford to pay for them. The pro- 

 gress of engineering works, if we consider it, and the expenditure upon 

 them, has already in our time been prodigious. One hundred and sixty 

 thousand miles of railway alone, put into figures at 20,000 a mile, 

 amounts to 3,200,000,000 sterling ; add 400,000 miles of telegraph at 

 100 a mile, and 100,000,000 more for sea-canals, docks, harbors, 

 water and sanitary works constructed in the same period, and we get 

 the enormous sum of 3,340,000,000 sterling expended in one genera- 

 tion and a half on what may undoubtedly be called useful works. The 

 wealth of nations may be impaired by expenditure on luxuries and 

 war; it cannot be diminished by expenditure on works like these. 



As to the future, we know we cannot create a force ; we can, and 

 no doubt shall, greatly improve the application of those with which 

 we are acquainted. What we called inventions can do no more than 

 this, yet how much every day is being done by new machines and in- 

 struments ! The telescope extended our vision to distant worlds. 

 The spectroscope has far outstripped that instrument, by extending 

 our powers of analysis to regions as remote. Postal deliveries were 

 and are great and able organizations, but what are they to the tele- 

 graph ? Need we try to extend our vision into futurity farther ? Our 

 present knowledge, compared with what is unknown even in physics, 

 is infinitesimal. We may never discover a new force yet, who can 

 tell? 



^ 



INSECTIVOROUS PLANTS. 



Br E. E. LELAND. 



MOST amateur botanists have in the course of their walks come 

 upon the peculiar leaves of the common sundew {Drosera ro- 

 tuncUfolia), with the clear drops which the leaves bear glistening in 

 the morning sun, and, on referring to their manuals, have noted the 

 relationship which it bears to Venus's fly-trap (Dioncea muscipula), 

 whose famous irritability is always a matter for mention. 



In collecting the showy side-saddle-flower (Sarrace?iia purpurea), 

 they have, of course, observed that its curious, trumpet-shaped leaves 

 are usually half-filled with water and drowned insects. 



In fishing from the stagnant pools, the inconspicuous, yellow blos- 

 soms, and rootless capillary leaves of the bladderwort ( Utricularia 

 vulgaris)^ they have doubtless noticed how they swarmed with insects 

 and small crustaceans ; and have accepted, with that unhesitating faith 

 which our whole system of education begets and fosters, the statement 

 that the little bladders are filled with air, and that their function is to 

 float the plant at the time of flowering. 



