CONTENTS
xiii
I. Oxygen Content of the Water . . .. . . 459
J. Hydrogen-ion Concentration
. . .. .. 460
K. The Effects of Turbidity . . .. .. . . 460
L. The Effects of Pollution . . .. .. . . 460
M. The Effect of Marine Foulings . . .. .. 462
N. Relation to other Borers . . .. .. .. 466
0. Parasites and Associates . . .. .. .. 467
XVIII. Objects Attacked . . .. .. .. .. .. 474
XIX. Detection and Prevention of Shipworm Attack
. . 475
XX. Timbers of Unusual Durability against Shipworms . . 478
A. The Role of Silica . . .. .. 1 . .. 480
B. Bark of Trees
.. .. .. .. .. 481
XXI. Acknowledgements
.. .. .. .. .. 482
XXII. References . . .. .. .. .. .. .. 482
AUTHOR INDEX . . .. .. .. .. .. 511
TAXONOMIC INDEX .. .. .. .. .. 529
SUBJECT INDEX . . .. .. .. .. .. 541
CUMULATIVE INDEX OF AUTHORS .. .. .. 565
CUMULATIVE INDEX OF TITLES . .
.. .. 567