926 FIUICES. 
limitation of the genera proposed in Hooker and Baker's ‘‘ Synopsis Filicum,’” 
that being the arrangement followed in the Handbook, Bentham’s ‘“ Flora 
Australiensis,’’ and other colonial floras, and the one acquiesced in by most 
English systematists. But European pteridologists as a rule accept a much 
larger number of genera, with a somewhat different sequence. And it must be 
admitted that Polypodiwm, Nephrodium, Aspleniwm, and other genera, as 
defined in the Synopsis, are for the most part artificial assemblages of species, 
possessing very diverse characters and relationships. But though it is com- 
paratively easy to separate a group here and there as being undoubtedly worthy 
of goperic rank, it is admittedly a matter of great difficulty to prepare good and 
natural generic subdivisions for the whole order, and although many attempts 
have been made not one of them has received a wide acceptance. The most 
recent classification is that given in Hingler and Prantl’s ‘‘ Die Naturlichen 
Pflanzenfamilien,’” where the class Filicales is divided into 12 familes and 
140 genera, against the 75 genera adopted in the ‘‘ Synopsis Filicum.” The 
31 genera of New Zealand ferns are spread out into 42 in the Pflanzenfamilien. 
The development of ferns can only be briefly alluded to here. In germina- 
tion 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 consist of minute subglobose bodies each 
containing numerous motile cells 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. Fertilisation 
is effected by the entrance of spermatozoids into the cavity of the archegonium, 
and by the fusion of one of them with the oosphere. The oosphere then gradually 
develops into a young plant. 
Since the publication of the Handbook several pamphlets or books dealing 
with the ferns of the colony have appeared. The most important of these 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 information, and should be consulted by all students of the order. 
Suborder I. HyMENOPHYLLACES. Sori always marginal, enclosed within @ 
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 .. +5 x a <- .. 1. HYMENOPHYL- 
LUM. 
Fronds membranous and translucent. Indusium urceolate 
or trumpet-shaped, entire or shortly 2-lobed .. .. 2. TRICHOMANES. 
Fronds coriaceous, opaque. Indusium urceolate, entire.. 3. Loxsoma. 
Suborder IT. CyYAaTHEACE®. Sori 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 ar boreous. 
Indusium globose, covering the young sorus, but soon 
bursting at the summit and persistent as a shallow cup 
surrounding the sorus at the base .. . 4. CYATHEA. 
Indusium never covering the sorus, small, half cup- shaped 
or semicircular, one-sided, not forming a Sone ae ring 
round the base of the sorus .. ae : .. 5. HEMITELIA. 
