File:Evolution and animal life; an elementary discussion of facts, processes, laws and theories relating to the life and evolution of animals (1907) (14770856554).jpg

Identifier: evolutionanimall00jord (find matches)
Title: Evolution and animal life; an elementary discussion of facts, processes, laws and theories relating to the life and evolution of animals
Year: 1907 (1900s)
Authors: Jordan, David Starr, 1851-1931 Kellogg, Vernon L. (Vernon Lyman), 1867-1937
Subjects: Evolution
Publisher: New York, D. Appleton and Company
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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l 17, 1906), Mr. C. B. Whitford maintains that betterresults in the trotting horse come from breeding from untrainedhorses of good blood than from horses which have been elabo-rately trained to the highest speed on the racecourse. Trotting horses that are overbred show the effects of their inten-sified breeding in a variety of ways. But the usual difficulty is ex-treme nervousness and want of ability to stand training. Sometimesa horse of this kind will show great promise when he is first hitched toa sulky. He will show great flashes of speed and will have a smooth,easy action and the trotting instinct well pronounced. But he is overnervous, lacks constitutional strength and willnot do well. The trouble with a horse of this kind is that he has not inheritedthe necessary fuel with which to create energy. He is burnt outby heredity. That which he needed to train on was so largely usedup by his ancestry in their process of development that they had notenough to transmit to their progeny.
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169 FIG. 101.—Diagram showing arrangement of bones in the hand or footof various animals : 1, man ; 2. gorilla ; 3, orang ; 4, dog ; 5, sea lion ; 6,dolphin; 7, bat; 8, mole; 9, Ornithorhynchus. (After Haeckel.) 170 EVOLUTION AND ANIMAL LIFE If this is true, it would appear that nervous overstrain ofthe parent is unfavorable to normal nerve development of theoffspring. This would be apparently a case of transmission ofparental conditions, as above indicated, and not one of trueheredity. It may be conceived that, at the moment of impregnation,the resultant germ cell is sexless. It begins its development atonce, and, in the higher animals, turns very soon toward theformation of those structures which distinguish the one sex orthe other. Each individual ultimately becomes either male orfemale. Relatively few animals, and those among the lower

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