H Hard Fern, 84 Hard Prickly Shield Fern, 59 Hartstongue, 82 Hay-scented Buckler Fern, 55 Holly Fern, 57 Horsetails, 6, 27, 31, 112 Life histories of, 21 _Hymenophyllaceæ_, 8, 33 _Hymenophyllum_, 131 _tunbridgensis_, 8, 35 _unilaterale_, 36 _Wilsoni_, 8, 37 I Indusium, 8, 14 Interrupted Club Moss, 106 _Isoëtaceæ_, 12 _Isoëtes_, 7 _hystrix_, 108 _Isoëtes lacustris_, 12, 107 L Lady Fern, 10, 66, 130 Lanceolate Spleenwort, 74 _Lastria æmula_, 55 _cristatum_, 53 _fæniscii_, 55 _filix-mas_, 46 _montana_, 50 _recurva_, 55 _rigidum_, 56 _Lepidodendraceæ_, 12 Lesser Alpine Club Moss, 106 Life histories of Club Mosses, 18 _et seq._ of Ferns, 3, 13 _et seq._ of Horsetails, 21 Little Adder’s Tongue, 98 Limestone Polypody, 130 _Lomaria spicant_, 84 _Lycopodiceæ_, 12 _Lycopodium_, 12, 19 _alpinum_, 105 _annotinum_, 106 _clavatum_, 12, 19, 101 _inundatum_, 19, 30, 104 _selago_, 19, 103 Lycopodium Powder, 32 M Maiden Hair, 9, 38, 41 Maidenhair Spleenwort, 78 Male Fern, 2, 10, 13, 46 Male organs (_see_ Antheridia) Malic acid, 18 _Marattiaceæ_, 11 Marsh Buckler Fern, 49 Marsh Club Moss, 104 Marsh Horsetail, 118 _Marsiliaceæ_, 12 Megasporangium, 20 Megaspores, 20 Microsporangium, 20 Microspores, 20 Moonwort, 11, 98 Mosses, 1 Mother cells, 15 Mountain Bladder Fern, 64 Mountain Buckler Fern, 50 Mountain Polypody (_see_ Beech Fern) N _Nephrodium æmulum_, 55 _cristatum_, 52 _dilatatum_, 54 _filix-mas_, 10, 13, 46 _montana_, 50 _oreopteris_, 50 _propinqua_, 49 _pseudo-mas_, 49 _rigidum_, 56 _spinulosum_, 53 _thelypteris_, 49 _uliginosa_, 54 O Oak Fern, 10, 90 Oblong Woodsia, 62 One-sided Filmy Fern, 37 _Ophioglosseæ_, 11, 96 _Ophioglossum lusitanicum_, 98 _vulgatum_, 11, 96 _Osmunda regalis_, 11, 93 _Osmundaceæ_, 11, 93, Ovum, 18 P Parsley Fern, 9, 44 Pepperworts, 12 Phanerogams, 22 _Philotaceæ_, 12 Pillwort, 2, 7, 12, 109 _Pilularia globulifera_, 12, 109 Pinnæ, 5 Pinnules, 5 Placenta, 14 _Plantago coronopus_, 69 Pollen grains, 27 _Polypodiaceæ_, 9, 10, 86 Polypodies, 86 _Polypodium alpestre_, 92 _calcareum_, 91 _dryopteris_, 10, 90 _phegopteris_, 10, 89 _vulgare_, 10, 86 _Polystichum aculeatum_, 59 _angulare_, 60 _lonchitis_, 57 Prickly Buckler Fern, 54 Prothallus, 17 _Pseudathryrium alpestre_, 92 _Pterideæ_, 38 Pteridosperms, 24 _Pteris aquilina_, 9, 38 Q Quillwort, 7, 107