Some Problems of Reproduction: a Comparative Study of ...

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PAOE 2. Colourless or Fungal Types . . .20 a. Phycomycetes zoosporete . . . 20 Ancylistese . . 20 Chytridieee (Olpidiopsis,Polyphagus,Zygochytrium,Tetrachytrium) . . .21 Monoblepharis . 22 Peronosporese. . 22 Saprolegniese . . 23 b. Phycomycetes aplanosporem . . 26 Entomophthorete . 26 Basidiobolus . . 26 Mucorini . . 27 c. Higher Fungi . . 28 Lower Ascomycetes 28 Lichens . . .28 Higher Ascomycetes, Basidiomycetes . 28 Ustilaginese . . 28 Protomyces . . 29 Uredinea; . .29 C. Higher Thallophytes . 29 1. Floridere . . . 29 Bangiacese . . .30 Eufloridete . . .30 (Secondary fertilisation) . . .31 Corallina . . 31 2. Characeee . .32 D. Archegoniata . . .32 1. Muscineas . . .32 2. Vascular Cryptogams . 34 E. SiphonoganiEe (Phanerogams) . . .35 1. Gymnosperms . . 35 Male structures (pollen and pollen tube) . 35 Archegonia . .35 MAJROtJS M. HAETOG. PAOE 2. Angiosperms . . 36 Male structures (pollen and pollen tube) . 36 Cell formations in embryo-sac . . .37 Cellular morphology of mature embryo-sac . 40 V. Comparative Gametogeny in the Animal Kingdom . 41 A. Protozoa. . . .41 1. Flagellata . . . 41 Euflagellata . . 41 Cystoflagellata (segmentation of zygote in Noctiluca) . . 41 2. JELhizopoda and Heliozoa 42 3. Gregarinida (Ophryocystis, Monocystis) . . 42 4. Hadiolaria . . . 43 5. Ciliata . . . . 43 Free Ciliata and Suctoria . . .43 Vorticellinea . . 47 B. Metazoa . . . .48 1. Spermatogeny . . 48 First mode. . .48 Second mode . . 49 Third mode . . 49 2. Oogeny . . . 50 Peculiarities of mature ovarian ovum or Gametogonium . 50 First nuclear changes . 51 Gametogenic fissions (formation of Oosphere and Polar Bodies) . . . 52 "Parthenogenetic ova" of the Metazoa . 53 VI. A General View of Gametogeny . . . .54 A. The Reduction of the Chromatom eres in Gametonuclei 54
SOME PROBLEMS OP REPRODUCTION. B. The Reproductive Incapacityof Obligatory Gametes 5 8 C. The Adaptation of Gametes to different Fates . .59 D. Analytic Summary of Gametogenic Processes . 60 (Alleged Excretion Proceases) . . .62 VII. The Causes of Protoplasmic Senescence and Ultimate Reproductive Incapacity 64 VIII. Protoplasmic Rejuvenescence, its Nature and Modes. . . .67 I. INTRODUCTORY. PAGE A. The Modes of Rejuvenescence. . . . G7 B. The Advantages of Karyogamy as compared with Agamy and Apogamy . 68 C. Allogamy and Sex . . 70 D. The Origin of Sex . . 72 E. Paragenetic Processes, usually comprised under the term " Parthenogenesis " . . .73 IX. General Conclusions THE curiouB phenomena preceding the maturity of the ovum in Metazoa have been the object of much study and the groundwork of much theory during the last fifteen years. Unfortunately processes occurring in this highly specialised group have been assumed to be typical of all organisms ; the authors who have put forward explanations of what they have seen here have too often sought to extend these explanations to other groups, where the facts are different; they have created homologies where none such exist in Nature, and overlooked those which lay under their eyes. In this way protoplasmic changes of various origin and functions occurring in Protozoa, Protophytes, and Higher Plants, have been interpreted as excretory processes, in order to make them fit in with the replacement theories of fertilisation, founded almost exclusively on the formation of the polar bodies in the Metazoan ovum. A careful study of the accessible materials in the gigantic storehouse of facts bearing on this subject has led me to the views which will be found in the following pages, namely : (1) That the most general, but not universal, feature underlying the preparations for fertilisation is the specialisation
Page 1: Some Problems of Reproduction: a Co
Page 5 and 6: 4 MABCUS M. HARTOG. of gametes by r
Page 7 and 8: 6 MARCUS M. HARTOG. MEMOIRS— "Sur
Page 9 and 10: 8 MARCUS M. HARTOG. also of karyoga
Page 11 and 12: 10 MARCUS M. HARTOG. Among the mari
Page 13 and 14: 12 MARCUS M. HARTOG. Chlamydomonas
Page 15 and 16: 14 MAKO[JS M. HAETOG. (Epithemia, A
Page 17 and 18: 16 MAECUS M. HARTOG. COLEOCHJETE^:
Page 19 and 20: 18 MARCUS M. HARTOG. indicating the
Page 21 and 22: 20 MARCUS M. HABTOG. VAUCHERIA is c
Page 23 and 24: 22 MARCUS M. HABTOG. The last two g
Page 25 and 26: 24 MARCUS M. HARTOG. mantle around
Page 27 and 28: 26 MARCUS M. HAETOG. Saprolegniese
Page 29 and 30: 28 MARCUS M. HARTOG. by the nuclei
Page 31 and 32: 30 MARCUS M. HAETOG. The BANGIACE-E
Page 33 and 34: 32 MARCUS M. HARTOG. 2. Characese.
Page 35 and 36: 34 MARCTTS M. HAETOG. in the great
Page 37 and 38: 36 MAEOUS M. HARTOGt. 2. Angiosperm
Page 39 and 40: 38 MAROUS M. HARTOG. mation of thes
Page 41 and 42: 40 MARCUS M. HAETOO. divisions of t
Page 43 and 44: 42 MAROUS M. HARTOG. of further vit
Page 45 and 46: 44 MARCUS M. HAKTOG. view is that i
Page 47 and 48: 46 MARCUS M. HARTOG. The following
Page 49 and 50: 48 MARCUS M. flARTOG. This confirms
Page 51 and 52: 50 MARCUS M. HARTOG. matogenygoes o
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52 MAROtJS M. HAKTOG. In the presen
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54 . MAEOTJS M. HAE.TOG. Though we
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56 MAROUS M. BARTOG. meres in the v
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58 • MARCUS M. HARTOG. asexual sp
Page 61 and 62:
60 . MABCTJS M. HABTOG. nay, in som
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62 . MARCUS M. HAHTOG. either direc
Page 65 and 66:
64 MAUCtJS M. HATJl'OG. We see that
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66 MARCUS M. HARTOG. Parallel cases
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68 MAECUS M. HAETOG. ciated, may oc
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70 MARCUS M. HAETOG. superBuities
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72 MARCUS M. HABTOG. D. THE ORIGIN
Page 75 and 76:
74 MARCUS M. HARTOG. zygote in the
Page 77 and 78:
76 MABCUS M. HAETOG. 4. Isogamy, pl
Page 79 and 80:
78 MABCUS M. HARTOG. heteroecism) i
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