Jliccia.] 
V. HEPATIC®. 
549 
branches linear-elongate, tips emarginate, 2-fid 01 forked; substance caver- 
nous towards the tips. — Syn. Hep. 610. 
^Northern Island : deep water, head of "Wairarapa valley, Colenso. (Europe, America, 
India, S. Africa.) 
Order VI. CKAEACEiE. 
Branching, submerged, slender, freshwater plants, with whorled branches, 
sometimes coated with carbonate of lime. Stems and branches formed of a 
few very long simple tubular cells placed end to end, with often smaller tubes 
on the surface of one central large one. Reproductive organs of two kinds ; 
1, solitary or clustered naked spores or nucules , each coated with spirally 
arranged cells, placed in the axils of the branches ; 2, spherical globules , all 
axillary, of a bright or dull red or orange colour, consisting of 8 triangular 
disciform scales ; in the centre of the inner surface of each scale a columnar 
tubular cell is fixed, which points towards the centre of the globule, and at 
its end bears a bundle of jointed threads, each joint (or cell) of which con- 
tains a spiral antherozoid. Gemmre are often produced on the root ; and 
stellate bodies, capable of reproducing the species, often replace the globules. 
A most curious Order of plants, abounding in many sluggish freshwater streams of tempe- 
rate climates, remarkable for the singular nature of its reproductive bodies, its obscure affini- 
ties, and the distinctness with which the circulation of the fluids in the stems and branches of 
many species may be seen with a low power of the microscope. 
Each node or joint of the stem or branches consists of but one length of cells, sometimes 
upwards of 1 in. long, with very transparent walls (except when coated with carbonate of 
lime), in which the sap may be watched, forming two currents side by side, and not separata! 
by anything, one ascending, the other descending. 
The spore (or nucule) consists of a central ovoid cell, full of starch-granules, coated by 
5 long cells spirally wound round it, their tips being free and having a cavity between them, 
down which the antherozoids are supposed to pass and impregnate the central cell. The spore 
germinates by the formation of a cell at its tip, from which rootlets descend and a stem 
ascends. 
The red globules (or antheridia) have their walls divided by three circles, two vertical, and 
three equatorial, and consist of eight disks, each of which is in shape an equilateral spherical 
triangle. Each disk is formed of radiating tubular cells ; a tubular cell proceeds from the 
centre of the disk to that of the globule, bearing at its apex a few small cells, from which 
the filaments, whose joints contain the spermatozoids, originate. 
The various species of the genus are very fetid, giving off an odour of sulphuretted 
hydrogen. 
I am indebted to my friend Professor A. Braun, of Berlin, for determining the New 
Zealand species of this Order. The specimens were in most cases insufficient for a full and 
satisfactory description. 
1. NITELLA, Agardh. 
Articulations of the stem and branches formed of 1 or more tubes, never 
coated with carbonate of lime. Crown of the nucule formed of about 10 
cells, in 2 series, usually deciduous. 
A large genus, found in all parts of the globe. 
* Eunitella. — Globules terminal at the forlcs of the branches. 
1. N. hyalina, Agardli. Monoecious; stem branched, rather stout. 
Whorls crowded, of many rays ; longer rays 8, 3 times forked, shorter about 
