2 FILICES. 
The development of ferns can only be briefly alluded to here. In germination the 
spore produces a small flattened or rarely filamentous prothallium, usually containing 
abundant chlorophyll, but without vascular tissue. It becomes quite free from the 
spore, but is of comparatively short duration. On the under-surface of the prothallium 
the reproductive organs are formed. The male organs are called antheridia, and con- | 
sist of minute subglobose bodies each containing numerous motile ceHs known as 
spermatozoids, resembling spirally coiled filaments, pointed at one end and _ bearing 
numerous cilia. The female organs, or archegonia, are flask-shaped bodies partly sunk 
in the tissue of the prothallium, each containing a single free cell called the oosphere. 
Fertilization is effected by the entrance of spermatozoids into the cavity of the archego- 
nium, and by the fusion of one of them with the oosphere. The oosphere then gradually | 
develops into a young plant. 
Prior to the publication of the first edition of this work several pamphlets or 
books dealing with the Ferns of the Colony have appeared. The most important are 
Mr. G. M. Thomson’s ‘Ferns and Fern Allies of New Zealand” and Mr. H. C. Field’s 
“Ferns of New Zealand.” Both of these contain much interesting and valuable 
matter, and should be consulted by all students of the family. An excellently illus- 
trated book on the Ferns of the Dominion, prepared by Mr. H. Dobbie, has also 
appeared wh le this acco nt was being written. 
Suborder I. HYMENOPHYLLACEAR. Sori always marginal, enclosed within a cup-shaped 
or urceolate entire or 2-valved indusium. Sporangia sessile or shortly stalked, arranged 
on a short or long columnar receptacle, girt by a complete horizontal or oblique ring. 
Fronds membranous and translucent (except in Loxsoma ). 
Fronds membranous and translucent. Indusium deeply 2-valved 1. HymENnopHyLium. 
fronds membranous and translucent. Indusium urceolate or 
trumpet-shaped, entire or shortly 2-lobed .. a .. 2, TRICHOMANES, 
Fronds coriaceous, opaque. Indusium urceolate, entire .. 93. Loxsoma. a 
WHO Keon a Ce me - 
Suborder II. CyATHEACEAR. Sort dorsal or marginal, naked or furnished with an 
indusium. Sporangia sessile or shortly stalked, arranged on a cushion-like receptacle, 
girt by a complete vertical or somewhat oblique ring. Stem often arboreous. 
___Indusium 2-valved, the upper valve continuous with the margin =o 
- of the frond .. i 4 = i. .. 4, Dicksonia, — 
Indusium globose, covering the young sorus, but soon bursting 
at the summit and persistent as a shallow cup surrounding the 
sorus at the base a ts a bs .. 5, CYATHEA, 
Indusium never covering the sorus, small, half cup-shaped or 
semicircular, one-sided, not forming a complete ring round the 
base of the sorus . ent 
~ 6, HEMITELIA. 
Indusium altogether wanting 7 
. ALSOPHILA. 
_ Suborder III. Potyropraceak. Sori dorsal or marginal, naked or furnished with an 
indusium. Sporangia with a short or long stalk, girt by an incomplete tertical ring, 
bursting transversely. Habit various. 
* Sori dorsal, remote from the margin of the frond. Indusium hooded or globose 
or reniform, opening all round its margin. 
Indusium hooded, ovate-deltoid, attached by a broad base .. 8 CYSTOPTERIS. 
Indusium orbicular and peltate a a. - .. 9. PoLystTicHum. i 
Indusium reniform, attached by the sinus. Fronds usually 2-4- 
pinnate ; pinnae not articulate on the rhachis 5: .. 10. DRyYoprTERIs. : 
Indusium wanting. Fronds pinnate; pinnae articulate on the 
rhachis Rc hes P, ih ons .. 11, ARTHROPTERIS, 
Indusium present, usually reniform. Fronds pinnate, articulated 
on the rhachis .. Ay s oe 5. .. 12. NEPHROLEPIS. 
** Sori marginal. Indusium opening outwards, or towards the margin of the frond, 
Indusium ovate, attached by a broad base, its free margin scal- 
Joped - aR? p — A .. 13. LEPTOLEPIA. 
Indusium cup-shaped, attached by both base and sides .. 14. DAvALura, 
Sori ‘linear. Indusium 2-valved; upper valve formed by the 
altered margin of the frond 4 ie gs .. 15. LINDSAYA. 
*** Sori lear or oblong, dorsal or submarginal. Indusium the same shape as the 
sorus ; opening inwards (towards the costa). 
Sori short, oblong, situated on a veinlet. Indusium inflated, 
straight or arcuate és ae co or .. 16, ATHYRIUM. 
