PAGE
1Portrait of AuthorFrontispiece
[2]Venus’s Fly-trap20
[3]Round-Leaved Sundew25
[4]Protomyxa Feeding34
[5]Fresh-Water Hydra37
[6]Star-fish Opening an Oyster45
[7]Common Earth-worms60
[8]Fiddler-Crabs72
[9]Warty Hermit-Crabs75
[10]Agalena and Her Funnel-Web79
[11]Lepismas at Work88
[12]You-ee-up in His Den91
[13]Seventeen-year Cicada97
[14]New-born Cicada99
[15]Dome-like House of Cicada101
[16]Blossom of Cucurbita105
[17]Nest of Lasius109
[18]Brachinus Pursued by an Enemy112
[19]Common Tiger Beetle117
[20]American Luna Moth123
[21]House-builder Moth129
[22]Pseudargiolus Butterfly134
[23]Violacea Butterfly138
[24]Neglecta Butterfly142
[25]Mourning-Cloak Butterfly146
[26]Leaf-Cutter Bee at Work150
[27]Battle Between Ants154
[28]Nest of Common Sun-fish159
[29]Black-nosed Dace163
[30]Common American Eel172
[31]Rana Clamata, or Green Frog177
[32]Common American Toad181
[33]Northern Rattlesnake189
[34]Mother Black Snake192
[35]Summer Green Snake195
[36]Water Snake196
[37]Common Box Tortoise201
[38]Summer Ducks and Young206
[39]American Woodcock214
[40]Female Piping Plover220
[41]Home of Bob White225
[42]Ruffed Grouse in Spring-time235
[43]Mexican Wild Turkey241
[44]Nest of American Osprey247
[45]Female Turkey Buzzard Dining259
[46]Nest of the Robin264
[47]Red-winged Blackbird’s Nest266
[48]Double Nest of Orchard Oriole268
[49]Female Baltimore Oriole270
[50]Acadian Flycatchers272
[51]Long-billed Marsh Wrens274
[52]Golden-Crowned Kinglets275
[53]Lace Hammock of Parula Warbler276
[54]Three-story Nest of Yellow Warbler278
[55]Saw-whet Owl and Chickaree Squirrel282
[56]Hackee, or Chipping Squirrel287
[57]My Dog Frisky292
[58]Tom on Duty297
[59]Jack at Dinner305
[60]Australian at Home311
[61]Representative Life of Western Asia319
[62]Seedling of Winter Grape325
[63]Tip of Radicle of Seedling Maple331
[64]Wonderful Equine Intelligence347
[65]Papier-Maché Palace of the Hornet353
[66]Unsolicited and Unlooked-for Kindness357
[67]Exhibition of Grandeur378
[68]Four Orphaned Robins389
[69]Mated for Life396
[70]Evidence of Conjugal Affection400
[71]Life in the Primordial Sea410
[72]Carboniferous Times412
[73]Mesozoic Flora and Fauna415
[74]Palæolithic Men Attacking Cave Bear448
[75]Era of Mind and Heart462

FULL PAGE PLATES.

From Photographs from Nature by A. Radclyffe Dugmore.

[1]Snapping Turtles FightingFrontispiece
FACING PAGE
[2]Crab Waiting for Food Under a Rock74
[3]Box-tortoise Feeding on Fungus200
[4]Woodcock on Nest (showing protective coloring)212
[5]Red-eyed Vireo’s Two-Storied Nest With Cow-bird’s egg beneath264
[6]Long-billed Marsh Wren’s Nest272
[7]Chipping Squirrels Feeding286
[8]Wood Thrush Setting402

LIFE AND IMMORTALITY.

LIFE AND ITS CONDITIONS.

All natural objects, roughly divided, arrange themselves into three groups, constituting the so-called Mineral, Vegetable and Animal kingdoms. Mineral bodies are all devoid of life. They consist of either a single element, or, if combined, occur in nature in the form of simple compounds, composed of more than two or three elements. They are homogeneous in texture, or, when unmixed, formed of similar particles which have no definite relations to one another. In form they are either altogether indefinite, when they are said to be amorphous, or have a definite shape, called crystalline, in which case they are ordinarily bounded by plane surfaces and straight lines. When mineral bodies increase in size, as crystals may do, the increase is produced simply by accretion. They exhibit purely physical and chemical phenomena, and show no tendency to periodic changes of any kind. Fossils or petrifactions, which owe their existence and characters to beings which lived in former periods of the earth’s history, cannot, though made up of mineral matter, be properly said to belong to the mineral kingdom.

But objects belonging to the vegetable and animal kingdoms differ markedly from inert, lifeless, mineral matter. Carbon, hydrogen, oxygen and nitrogen are the most important of the few chemical elements which enter into their composition, and these elements are combined into complex organic compounds, which always contain a large percentage of water, are very unstable, and prone to spontaneous decomposition. They are composed of heterogeneous, but related, parts, termed organs, the objects possessing them being called organized bodies. Some of the lowest forms of animals have bodies whose substance is so uniform that they exhibit no definite organs, but this exception does not affect the general value of this distinction. They are always more or less definite in shape, presenting concave and convex surfaces, and being limited by curved lines. When they increase in size, or grow, as we properly term it, it is not by the addition of particles from the outside, but by the reception of foreign matter into their interior and its consequent assimilation. Certain periodic changes, which follow a definite and discoverable order, are invariably passed through by organized bodies. These changes constitute what is known as life. All the objects, then, which fulfil these conditions are said to be alive, and they all appertain either to the vegetable or the animal kingdom. The study of living objects, no matter to which kingdom they belong, is therefore conveniently called by the general name of Biology, which means a discourse on life. And as all living objects may be referred to one or other of these kingdoms, so Biology may be divided into Botany, which treats of plants, and Zoölogy, which treats of animals.

Now that we have divided all organized bodies into plants and animals, it becomes necessary to inquire into the differences which subsist between them, and which will enable us to separate the kindred sciences of Botany and Zoölogy. Nothing was thought so easy by older observers than the determination of the animal or vegetable nature of any given organism, but, in point of fact, no hard-and-fast line can be drawn, in the existing state of our knowledge, between the animal and vegetable kingdoms, and it is sometimes difficult, or even impossible, to decide with positiveness whether we are dealing with a plant or an animal. In the higher orders of the two kingdoms there is no difficulty in reaching a decision, the higher animals being readily separated from the higher plants by the possession of a nervous system, of a locomotive power which can be voluntarily exercised, and of an internal cavity adapted for the reception and digestion of solid food. No so-called nervous system or organs of sense are possessed by the higher plants, although some of them doubtlessly manifest conscious and intelligent action, nor are they capable of voluntary changes of place, nor provided with any definite internal cavity, their food being generally fluid or gaseous.

Descending the scale to the very bottom, we reach a class of animals, the Protozoa, which cannot be separated in many cases from the Protophyta by these distinctions, since many of the former have no digestive cavity, nor the slightest trace of a nervous system, while many of the latter possess the power of active locomotion. As to external configuration, no certain rules can be laid down for separating animals and plants, many of the lower plants, either in their earlier stages, or in their maturity, being exactly similar in form to some of the lower animals. This is the case with some of the Algæ, which resemble very closely in form certain Infusorian animalcules. Again, many undoubted animals, which are rooted to solid objects in their adult state, are so plant-like in appearance as to be popularly regarded as vegetables. The Sea-firs, and the more highly organized Flustras or Sea-mats, which are usually considered as sea-weeds by sea-side visitors, are a few of many examples that might be taken from the so-called Hydroid Zoöphytes. No decided distinction between animals and plants can be drawn as to their minute internal structure, both alike consisting of molecules, of cells, or of fibres. Some decided, though not universal, differences exist in chemical composition. Plants exhibit a decided predominance of ternary compounds, or compounds which, like sugar, starch and cellulose, are made up of the three elements, carbon, hydrogen and oxygen, but are, comparatively speaking, poorly supplied with quaternary compounds, or those which contain an additional element of nitrogen. Animals, on the contrary, are rich in quaternary nitrogenized compounds, such as albumen or fibrin. Still, in both kingdoms we find nitrogenized and non-nitrogenized compounds, and it is only in the proportion which these sustain to each other in the organism that animals differ in any way from plants.