Hunter, _Laboratory Problems in Civic Biology_. American Book Company. Beebe, _The Bird_. Henry Holt and Company. Bigelow, _Applied Biology_. Macmillan and Company. Davison, _Practical Zoology_. American Book Company. Herrick, _Household Insects and Methods of Control_. Cornell Reading Courses. Hornaday, _Our Vanishing Wild Life_. New York Zoological Society. Hodge, _Nature Study and Life_. Ginn and Company. Kipling, _Captains Courageous_. Charles Scribner's Sons. Sharpe, _Laboratory Manual_, pp. 157-158, 182-203, 320-341. American Book Company. Stone and Cram, _American Animals_. Doubleday, Page and Company. Toothaker, _Commercial Raw Materials_. Ginn and Company. ADVANCED Flower, _The Horse_. D. Appleton and Company. Hornaday, _The American Natural History_. Macmillan and Company. Jordan, _Fishes_. Henry Holt and Company. Jordan and Evermann, _American Food and Game Fishes_. Doubleday, Page and Company. Schaler, _Domesticated Animals, their Relations to Man and to His Advancement in Civilization_. Charles Scribner's Sons. XVI. THE FISH AND FROG, AN INTRODUCTORY STUDY OF VERTEBRATES _Problems._--_To determine how a fish and a frog are fitted for the life they lead._ _To determine some methods of development in vertebrate animals._ _(a) Fishes._ _(b) Frogs._ _(c) Other animals._ LABORATORY SUGGESTIONS _Laboratory exercise._--Study of a living fish--adaptations for protection, locomotion, food getting, etc. _Laboratory demonstration._--The development of the fish or frog egg. _Visit to the aquarium._--Study of adaptations, economic uses of fishes, artificial propagation of fishes. Two Methods of Breathing in Vertebrates.--Vertebrate animals have at least two methods of getting their oxygen. In other respects their life processes are nearly similar. Of all vertebrates fishes are the only ones fitted to breathe all their lives under water. Other vertebrates are provided with lungs and take their oxygen directly from the air.[32] We will next take up the study of a fish to see how it is fitted for its life in the water. Footnote 32: With the exception of a few lungless salamanders. Most salamanders get much of their supply of oxygen through their moist skins. STUDY OF A FISH