38 
INDEX 
References are to pages 
Trout, example of fish 
9 
Umbrella-shaped branches of 
bony fish. 
71 
marchantia. 
331 
Trunk region of fish . . 
71 
Underground stems, described . 
261 
Trunks of evergreens . . 
341 
examples of. 
261 
Trypsin, an enzyme . . 
412 
of pteris. 
333 
Tsetse fly, sleeping sickness 
Undissolved food. 
415 
spread by ... . 
494 
Unhealthy cows, milk from . 
315 
Tube feet of starfish . . 
171 
Unicellular fungus, yeast an 
Tuberculin test, for cows 
315 
example. 
321 
discovered by Koch 
315 
United States Government De¬ 
Tuberculosis, a bacterial 
dis- 
partments . . . 500, 505, 
525 
ease. 
449 
Univalves. 
189 
discussed. 
489 
Unusual plants. 
in cows. 
315 
Unwashed hands, number of 
of throat and other organs . 
492 
bacteria on. 
312 
treatment for .... 
491 
Ureter, of frog. 
87 
Tubular appendages of male 
of man.. . 
458 
crayfish . 
64 
Urethra, of man. 
458 
Tubular flowers . . . 
206 
Urinary bladder of frog . 
87 
Tubules of kidney . 
458 
Uriniferous tubule. 
458 
Tulip tree. 
364 
Useful birds, examples of 114, 
115 
Tumors. 
488 
Uses, of fruits to man 
244 
Turgid cells. 
of parts of a flower .... 
202 
Turnip, example of biennial 
of stem, to man. 
261 
root. 
252 
to plant. 
261 
member of mustard family . 
298 
of terms “fruit,” “seeds,” 
storage of food in 
255 
etc. 
245 
Turpentine, source of . . 
346 
of wood. 
347 
Turtle, example of Reptilia 
100 
green, use of, as food . 
100 
V 
skeleton of .... 
100 
Turtles, discussed . . . 
100 1 
Vaccination, discussed . 507, 509 
Twining petiole, of clematis 
290 
Vaccine. 
510 
Twining stems .... 
260 j 
Vacuole, food, of amoeba . . 
144 
Two-parted flower of mint 
300 
contractile. 
145 
Tympanic cavity . . 
475 
Vacuoles, in nerve cells . 
481 
Types of cattle, discussed 
130 
Valves, of veins. 
453 
Types of heads of oats 
390 
of clam shell. 
185 
horses discussed 
126 
of stomach. 
408 
pigs discussed 
133 
Vapor, a form of water . . . 
10 
sheep discussed . 
132 
Variation. 
526 
Typhoid fever, a bacterial 
dis- 
Variations, in beaks of birds 
109 
ease. 
489 
in legs of birds. 
108 
spread by carriers . . 
500 
Varied diet of man .... 
411 
Typhus fever .... 
514 
Variety of animal life .... 
17 
Typical fern, pteris . . 
333 
Varnish, source of. 
352 
Vascular bundles, arrangement 
u 
of. 
267 
formation of tubes by . 
266 
Ulmus americana . . 
10 
of root (conducting vessels) . 
248 
Umbel. 
213 
of woody stems. 
267 
