. Plants of New Zealand. Fig. 1-23. 1. V. propinqua. 2. V. tetrasticba. 3. V. Hectori. 4. V. V. elliptica. 6. V. epacridea. 7. V. cupressoides. show a like heterophylly, as it may be termed, areHelichrysum {Ozothamnus) coralloides, Baoulia hryoides, andBaoulia Tnammillaris. There can be but little doubt that, ineach case, the larger leaved form is the ancestral one. Itmay therefore be expected, in accordance with the ordinarylaw {v. p. 256), that the seedling form in its developmentwould pass through a stage with large leaf-surfaces. Sucha stage is often termed a reversion shoot
. Plants of New Zealand. Fig. 1-23. 1. V. propinqua. 2. V. tetrasticba. 3. V. Hectori. 4. V. V. elliptica. 6. V. epacridea. 7. V. cupressoides. show a like heterophylly, as it may be termed, areHelichrysum {Ozothamnus) coralloides, Baoulia hryoides, andBaoulia Tnammillaris. There can be but little doubt that, ineach case, the larger leaved form is the ancestral one. Itmay therefore be expected, in accordance with the ordinarylaw {v. p. 256), that the seedling form in its developmentwould pass through a stage with large leaf-surfaces. Sucha stage is often termed a reversion shoot. Reversions 374 PLANTS OP NEW ZEALAND to the earlier form are, however, not necessarily confined toyoung plants, but are also sometimes found upon the maturespecimen. Unfortunately, but little attention has hitherto been givento the leaf-forms of the whip-cord Veronicas. Prof. Goebel,. Fig. 124. 1. He)icln-j sum luicrophyllum. \i. H. coralloides. 3. H. iuiLTO))iiytluiii ivar.)4. Veronica lycopodioides. 5. Libocedrus Bidwillii. 6. V. Tetrasticba. the famous botanist of Munich, was the first to study themexperimentally, and, after him, Mr. E. Brown, of Christchurch,showed how extremely plastic these strange forms are. It be regretted, that the latter has not published an accountof his experiments, in some accessible scientific , however, Dr. Cockayne, in his valuable studies onthe germination of New Zealand seedlings, has carefullyinvestigated the younger stages of a considerable number ofspecies of Vero7iica. THE SNAP-DRAGON FAMILY 375 He has found, that in several cases at least, the seedlingpasses through a stage with large leaves, unlike those of themature form. The development of Veronica tetrasticha maybe taken as an example. It is a beautiful little sub-alpineplant, with tetrangular stem and cupressoid leaves. collected seed
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