FERN ALLIES OP NEW ZEALAND. 21 



<;edar-wood handles, about as thick as a penholder, and 3 or 4 inches 

 long. Special needle-holders made of bone or ivory may be 

 3)\irchased from all microscope makers, but the simpler instrument 

 will be found a very satisfactory substitute. A pair of good strong 

 forceps completes the requisite apparatus. In examining a portion 

 of a frond in the dissecting microscope, the piece should be placed 

 on the slide of the glass table of the instrument in a drop of water ; 

 practise will enable the student to judge the exact amount of water 

 required. Holding the fragment down with the left-hand needle, 

 parts may be cut off, removed or turned in any direction with 

 that in the right hand, the lens being focussed down to the right 

 •distance. 



Order L— FILICES (True Ferns). 



The arrangement of the genera adopted here is that of the 

 " Synopsis Filicum," but the plants constituting the sub-order 

 Ophioglossacese have been removed from among the true ferns and 

 placed in a distinct order by themselves. 



Tribe I. — Gleicheniacese. Capsules solitary or grouped into small 

 sori of a definite number (2-6), sessile, globose, completely girt by a 

 ■broad, transverse or oblique ring, and opening vertically. No in- 

 voVacre. (PI. I. fig. 1.) 



Khizome creeping. Fronds rigid, coria- 

 ceous, mostly dichotomously branched ; 

 segments of the pinnse small and 

 round, or elongated and conablike ... 1. Gleichenia. 



Tribe II. — Oyatheacese. Sori globose, dorsal, formed of nwmerous 

 capsules ; these are either sessile or stalked on a somewhat elevated 

 receptacle, and are often mixed with jointed hairs. They are obovate 

 in form and somewhat compressed, and are furnished with a broad 

 vertical or oblique ring. {The tree ferns belong to this tribe.) PI. I. 

 figs. 2-5. 



I. — Sori at or near tlie forking of a vein. 



Involucre globose and at first covering the 

 ■whole sorus, afterwards breaking ir- 

 regularly at the summit and leaving a 

 cup with smooth or torn edges; large 

 tree-ferns 2. Cyathea. 



Involucre a scale (often indistinct) on the 

 underside of the sorus; a large tree- 

 fern 3. Hemitelia. 



Involucre wanting ; a small tree-fern ... 4. Alsophila. 



