Organography of plants, especially of the archegoniatae and spermaphyta . eing better fed, where broad wings have developed,beneath which drops of water (in-dicated by dots) collect. very poor in nutriment. Prothalli of Polypodiaceae wanting the Heart-like Outline. Anogramme. The prothallus of the genus Anogramme connects withthe forms in which the formation of the two wings takes place at different How they arise we shall not stop to inquire. 2o6 CONFIGURATION OF THE PROTHALLUS OF PTERIDOPHYTA times. On account of its noteworthy adaptations it will be mentionedparticularly below ^. It produce
Organography of plants, especially of the archegoniatae and spermaphyta . eing better fed, where broad wings have developed,beneath which drops of water (in-dicated by dots) collect. very poor in nutriment. Prothalli of Polypodiaceae wanting the Heart-like Outline. Anogramme. The prothallus of the genus Anogramme connects withthe forms in which the formation of the two wings takes place at different How they arise we shall not stop to inquire. 2o6 CONFIGURATION OF THE PROTHALLUS OF PTERIDOPHYTA times. On account of its noteworthy adaptations it will be mentionedparticularly below ^. It produces only, if one may so say, one wing withlateral meristem, behind which there is formed a peculiar tuberous arche-goniophore. The prothallus with heart-like outline is here never reached. Vittariaceae. The Vittariaceae also have not prothalli with heart-likeoutline in the cases which have been accurately investigated. There arisesin the first instance a simple cell-surface with marginal growth. Thisdivides into lobes (Fig. 152), through isolated portions of the meristic. Fig. 152. Vittaria. 1-6, Formation of protliallus ; Ar, arcliegonia; E, embryo ; Br, gemmae,magnified. The others slightly magnified. I, highly margin passing into a permanent condition, and thus there is developeda highly irregular lobed body in some ways resembling the flat protonemaof Sphagnum, and it forms marginal groups of archegonia which, primarilyarising in the meriscem, are separated from it at a later time by the portionswhich have passed into the permanent condition. Hymenopliyllum. The form of prothallus of Vittariaceae leads us tothat of Hymenophyllum. Here we have also to do with a richly-branched, See p. 216. PROTHALLI OF POLYPODIACEAE—NOT HEART-SHAPED 207
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