43. " and ectozoa of bats 295 44. " of insectivorous mammals 297 45. " of carnivorous mammals 310 46. " of seals 315 47. " of rodents 320 48. " of sloths and ant-eaters 322 49. " of ruminants 352 50. " and ectozoa of solipeds 389 51. " " of elephants 400 52. " of rhinoceroses 402 53. " of the hippopotamus and tapir 403 54. " and ectozoa of swine 414 55. " of whales, dolphins, and dugongs 429 56. " of marsupial animals 434 57. " and ectozoa of birds 448 58. " of reptiles 456 59. " and ectozoa of fishes 477 60. " of insects, crustaceans, and mollusks 484 ERRATUM. Page 296, line 24 from the top, for “in the glow-worm (_Glomeris_),” read “in a myriapod (_Glomeris_) which is phosphorescent like the glow-worm.” PARASITES. INTRODUCTION. No person can derive advantage from the study of parasites unless the subject be approached in a right frame of mind. In other words, the student of helminthology must, as a primary discipline, dispossess himself of all preconceived opinions whatsoever, and in an attitude of child-like simplicity seek truth for its own sake. Unless the mind be absolutely free and unfettered it cannot rightly interpret the facts of this peculiar department of biological science. Those students who are nervously anxious to reconcile the conclusions of modern science with the ideas of their forefathers are certain to remain just as ignorant of the true value and significance of nature-teachings as all their fathers were.