- Unit characters, [258].
- Ureter, [342].
- Urethra, [342].
- Urine, [341].
- Urodela, [188].
- Uses, of animals, [198];
- Uterus of a mammal, [247].
- Vaccination, [157], [221], [391].
- Vacuoles, contracting, [168].
- Value, of insects, [208];
- of trees, [105].
- Valves, [185], [319];
- in vein, [324].
- Variation, [250].
- Vasomotor nerves, [325].
- Vegetable fibers and oils, [127].
- Veins, [318];
- Venæ cavæ, [322].
- Ventilation, [335], [338].
- Ventricle, [319];
- of fish heart, [236].
- Venus fly trap, [102].
- Vermiform appendix, [309].
- Vertebral column, [186].
- Vertebrates, breathing of, [232].
- Villi, [308].
- Virginia creeper, [128].
- Virus, [392].
- Vitreous humor, [361].
- Vorticella, [171], [178].
- Vries, Hugo de, [253], [406].
- Warner, Chas. Dudley, [211].
- Waste of food, [287].
- Water, [275];
- Weed, [48], [128].
- Weights, [417].
- Wheat crop, [121], [122].
- Wild orchid, [40].
- Windpipe, [300], [301].
- Wood, uses of, [110].
- Work of cells, [270];
- Worms, [183].
- Zygospore, [174].
Transcriber's Notes:
Punctuation, use of hyphens, and accent marks were standardized. Obsolete and alternative spellings were left unchanged. Spelling of 'paramœcium' and 'paramœcia' were left unchanged.
Footnotes were moved to the end of the chapter in which the anchor occurs. Footnote anchors [6] and [7] refer to the same footnote text, as do footnote anchors [37] and [38].
A jump table was added to the index for the convenience of users.
For consistency within the text, 'zoological' was changed to 'zoölogical' and 'diarrhea' to 'diarrhœa.'