xxiv] 



PHYLETIC GROUPING 219 



I. Gleichenia, Smith. 1793- 79 ^pecies. 

 i. Suh-genus Dicranopteris,B&vnh. 1806. 



Includes probably the most primitive types, as shown by their large 

 output of spores persporangium,and of spermatocytes per antheridium. 



Protostelic axis. Protective scales, 

 ii. Sub-genus ^w-6^/^zV/^^/«'^, Hooker. 1846. 



Specialised xerophytes, with reduced leaf-surface, fewer sori, and 



sporangia, and lower spore-output from each. Protostelic axis. 



Protective scales, 

 iii. Sub-genus Eu-Dicrmwpteris, Bower. 1925. 



Habit oi Dicranopteris, but with hairs only. Sorus crowded, with as 



many as 10 or 12 sporangia, and a lower spore-output from each. 



Advanced stelar structure in G. pectinata. 



II. Strom ATOPTERis Mettenius. 1861. i species. 



Specialised xerophyte: scales and hairs: spore-output rather high. 

 Protostelic rhizomatous axis. 



III. Platyzoma, R. Br. 1810. I species. 



Specialised xerophyte, hairs, not scales: heterophyllous: initial sole- 

 nostely: annulus horizontal to vertical with lateral dehiscence: very 

 low spore-output per sporangium: initial heterospory. 



BIBLIOGRAPHY FOR CHAPTER XXIV 

 Rauwenhoff. La Gen. Sex. d. Gleicheniacees. Arch. Need. xxiv. 1891. 



477. Bower. Studies IV. Phil. Trans, cxcii, p. 29. 1899. 



478. BOODLE. Anatomy of the Gleicheniaceae. Ann. of Bot. xv, p. 703- iQoi- 



479. Engler & Prantl. Naturl. Pflanzenfani. i. 4, p. 350- 190-- 

 ^yc) bis. Tansley. Ann. of Bot. xix, p. 477- I905- 



479 /r/j. Tansley. New Phyt. vi, p. 135. 1907- 



480. Underwood. Bull. Torrey. CI. 34, p- 243- iQo?- 



480 ^/J Campbell. VroXh^Wus oi Kaulfussia2ind Gleichenia. \m-\.oi]^r A. V,mt. vni, p. 69. 



476 



481. Bower. Origin of a Land Flora. 1908, p. 553. 



482. Seward. Fossil Plants. Vol. ii, p. 35i- i9io- 



483. Bower. Studies H. Ann. of Bot. xxvi, p. 269. 1912. 



484. Thompson. Kn?iiomY oi Platyzoma. Tran. Roy. Soc. Edin. h, Part 111, p. 631. 1916. 



485. Thompson. A further contribution on Platyzoma. Trans. Roy. Soc. Edin. In, 



Part i, p. 157- 



486. Thompson. Stromatopteris. Trans. Roy. Soc. Edin. In, Part i, p. i33- 'Qi?- 



487. Thompson. Morph. of the stele oi Platyzoma. Trans. Roy. Soc. Edin. In, Part ni, 

 p. 571. 1919. 



488. GOEBEL. Organographie. 11 Aufl., p. io43- iQiS- Also Eng-. Edn., p. 31^- 



489. Campbell. Mosses and Ferns. 3rd edn., pp. 366, 635. 1918. 



490. Scott. Studies in Fossil Botany. 1920, p. 263. 



491. Compton. Plants collected in New Caledonia. Linn. Journ. xlv. p. 453- 1922. 



492. Seward. Hooker Lecture. Linn. Journ. xlvi, p. 219. 1922. 



