374 
THE FLORIST. 
and are in fact the prima facie characters which are universally 
employed in distinguishing them. 
Diagram showing some op the Principal Forms of Venation.— (a, b , c), free; ( d , e ), 
connivent; (/, g), combined; (h, i, k, l, m), reticulated, (a), simple, e.g. Pleurogramma; 
(6), parallel-forked, with clavate apices, e. g. Scolopendrium; (c), pinnate, e. g. some sp. of 
Grammitis : (d), connivent, e. g. Callipteris ; (e), connivent, with excurrent veinlets, e. g. 
Goniopteris ; (/), combined, transverse-marginal, e. g. Thamnopteris; (g), combined, trans¬ 
verse-costal, e. g. Woodwardia; (7i), arcuately-anastomosing, with excurrent veinlets, e. g. 
Campyloneurum ; ( i), convergent-reticulated, e.g. Phlebodium ; (7c), uniform-reticulated, with 
oblique hexagonal areoles, e.g. some sp. of Litobrocliia; (l), semi-reticulated, e. g. Hemidictyon ; 
(m ), compound-reticulated, e. g. Drynaria. The above figures represent the venation on one 
side the costa. 
The venation in Ferns may be divided into four classes:— (a), free, 
i. e ., where the veins are continued without coming in contact with 
each other; ( b ), connivent, i. e., where all having an excurrent or 
outward tendency, they coalesce angle wise ; (c), combined, i. e., where 
a longitudinal vein unites continuously with other veins ; and ( d ), re¬ 
ticulated, i. e., where they form a complete network, being united in 
every direction. Few of the multiform varieties of venation have par¬ 
ticular names, but there are some terms applied definitely, which we 
may here explain. Among the free veins, those are called simple, which 
proceed from the. costa unbranched, and the same term is used in 
reference both to venules and veinlets when unbranched; those are 
said to be forked, which branch once or more in a dichotomous manner, 
the branches being equal, that is nearly or quite uniform in substance; 
the term parallel forked is applied to a form of free forked venation, in 
which the branches are of considerable length, and proceed near to and 
parallel with each other ; and those are said to be pinnate, which have 
the vein itself, i. e., the first series from the costa, stronger than the 
rest—somewhat costa-like, in fact—and branching equally on both 
sides. The pinnate vein often occurs in connection with connivent ond 
reticulated venules and veinlets. In the connivent form of venation 
