Maupas_1900

MODES AND FORMS OF REPRODUCTION OF NEMATODES. 181

MODES AND FORMS OF REPRODUCTION OF NEMATODES. 183

MODES AND FORMS OF REPRODUCTION OF NEMATODES. 185

TABLE OF CONTENTS

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Introduction ………………………………………………………………………………………………………1

Method………………………………………………………………………………………………………………14

Rhabditis Caussaneli: Description………………………………………………………………………34

-- Biology……………………………………………………………………………39 Rhabditis Marionis…………………………………………………………………………………………….47

-Duthiersi……………………………………………………………………………………………..55

-Perrieri………………………………………………………………………………………………..61 Rhabditis Guignardi…………………………………………………………………………………………..66

-Viguieri……………………………………………………………………………………………….71

-dolichura…………………………………………………………………………………………….75

-coronata…………………………………………………………………………………………….……81

Diplogaster robustus…………………………………………………………………………………………..86

-minor……………………………………………………………………………………………….95

Rhabditis Schneideri…………………………………………………………………….…………………..100 Cephalobus dubius…………………………………………………………………………………………….102

-lentus………………………………………………………………………………………………110

Plectus cirrata…………………………………………………………………………………………………..115 Aphelenchus agricola…………………………………………………………………………………………119

Alaimus Thamugadi………………………………………………………………………………………….123

Macrolaimus crucis…………………………………………………………………………………………..126 Summary and conclusions…………………………………………………………………………………..131 I. Distribution and frequency of hermaphroditism and parthenogenesis…………….131

II. The hermaphroditic and parthenogenetic species are morphologically similar to

their dioic congeners………………………………………………………………………………………….132 III. Protandrous dichogamy and strict self-fertilization of hermaphrodites…………133 IV. Imperfection of protandrous hermaphroditism…………………………………………..135 V. Rare males of hermaphroditic species………………………………………………………….137 VI. Abolition of the sexual instinct of these males……………………………………………..139 VII. These atavistic males are the surviving witnesses of an ancient dioic state……141 VIII. Partial and incomplete hermaphroditism…………………………………………………142 IX. Origin of hermaphroditism……………………………………………………………………….143

MODES AND FORMS OF REPRODUCTION OF NEMATODES. 187

X. Normal hermaphroditism is specific to females……………………………………………148 XI. Equivalence of the genital elements……………………………………………………………150 XII. Heterogamous refertilizations with arrhenotokous tendency………………………151 XIII. Sexual determinism……………………………………………………………………………….152 XIV. In principle self-fertilization is not harmful………………………………………………159 XV. Parthenogenesis……………………………………………………………………………………..162 XVI. Flexibility and malleability of the genital organs……………………………………….164 Appendix: on molt and encystment…………………………………………………………………165 Explanation of plates……………………………………………………………………………………..170