Breeding of farm animals / by Merritt W. Harper.

  • Harper, Merritt W. (Merritt Wesley), 1877-
Date:
1914
Catalogue details

Licence: In copyright

Credit: Breeding of farm animals / by Merritt W. Harper. Source: Wellcome Collection.

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    CONTENTS CHAPTER I Page Introduction v 1 Farm animals provide labor, food and clothing—Num- ber and value of farm animals—Human population in- creasing, number of farm animals decreasing—Farm animals costly—Relation of food, to production—Distri- bution of farm animals—Improving farm animals—En- vironment—Heredity—Selection—Propagation of animals. CHAPTER II Reproductive Organs and Germ Cells 10 Female reproductive organs—Male reproductive organs —The cell—Cell division—The chromosomes—The germ cells—The egg cell—The sperm cells—Chromosome re- duction—Fertilization. CHAPTER III The Determiners of Heredity 21 Darwin’s Pangenesis—Weismann’s germ plasm—Op- posite views—Approved practice not involved—The hereditary bridge—The hereditary material—The enzyme theory—The chromosome theory—Chromosome combina- tion—Origin of hereditary material—Basis of controlling determiners of heredity. CHAPTER IV Heredity in Animal Breeding 31 Brewer’s fundamental propositions—Complex nature of heredity—Offspring in general resemble parents— Particular offspring unlike the parent—Some offspring higher and some lower than their parents—Medium off- spring the most frequent—The high parent and his off- spring—The high offspring and his parents—The law of ancestral heredity—Reversion and atavism—Blended, ex- clusive and particulate inheritance.