376 NOTES. 
may be terrific to a Fly; and while Flies hear one another, they take no 
notice of the human voice. 
113 An exception to the general rule that the smaller animals have more 
acute voices. 
114 Tt is wanting in a few, as the Storks. 
115 The Nightingale and Crow have vocal organs similarly constructed, 
yet one sings, and the other croaks. 
116 The three methods are substantially alike; for an egg is only a sepa- 
rated bud. In the lower organisms, the parent is completely broken up 
into new individuals; in the higher, new individuals form but an infinitesi- 
mal part (germ) of the parent. Under any form, reproduction is a process 
of disintegration. Some Protozoa do not appear to produce by eggs. 
117 These cells are detached portions, or buds, of the parental organisms. 
Generally, these two kinds of cells are produced by separate sexes; but in a 
few cases, as the Snail, they originate in the same individual. Such an ani- 
mal, in whom the two sexes are combined, is called an hermaphrodite. 
118 Tf an egg be violently shaken, this connection is broken; and this is 
the secret of making an egg stand on end without breaking it, as Columbus 
is said to have done. 
19 The eggs of Mammals are of nearly uniform size; those of Birds, In- 
sects, and most other animals are proportioned to the size of the adult. 
Thus, the egg of the Apyornis, the great extinct bird of Madagascar, has 
the capacity of 50,000 Humming-birds’ eggs. 
120 As a general rule, when both sexes are of gay and conspicuous colors, 
the nest is such as to conceal the sitting Bird; while, whenever there is a 
striking contrast of colors, the male being gay and the female dull, the nest 
is open. Such as form no nest are many of the Waders, Swimmers, Scratch- 
ers, and Goatsuckers. 
121 As the Crocodile, by its gizzard and its rude nest, looks forward, so the 
pouched Kangaroo looks backward, to the true ornithie type. 
122 This rudiment lies transversely to the long axis of the eg; and as the 
chick develops, it turns upon its side, so that the forepart of the head usual- 
ly faces the narrow end of the egg. 
123 The blood comes into being before the blood-vessels, and veins before 
arteries; 7. e., the very first motion is toward the heart. The blood is first 
yellowish. The red corpuscles are supposed to be derived from the nuclei 
of the white corpuscles: the origin of the latter is undetermined. 
124 Exactly as the blood in the capillaries of the skin is aérated by the ex- 
ternal atmosphere. 
125 Thus, the hollow wing-bone was first solid, next a marrow-bone, and 
finally a thin-walled air-cell. The solid bones of the Penguin are examples 
of arrested development. 
126 The thigh-bone of the child consists of five distinct parts; in the adult, ° 
they are united into one. 
‘27 Muscle is mainly fibrine, while nerve is chiefly albumen. 
128 This generalization must not be confounded with the old statement, 
which is not true, that the higher animals pass through all the phases of 
the lower life. See Spencer’s ‘Principles of Biology,” i., 148; Clark’s 
““Mind in Nature,’’ 159. 
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