in Blechnum and Osmunda. 
29 
Schacht 1 belongs the credit of bringing these remarkable 
structures more prominently into view by describing and 
figuring them in his paper in Pringsheim’s Jahrbuch. Besides 
the intercellular hairs other resin-secreting trichomes of similar 
structure occur on the paleae of various species of Aspidinm . 
Thus de Bary 2 mentions Aspidium Filix-mas , Sw., Aspidium 
spinulosum , Sw., and Aspidium molle , Sw., as possessing 
capitate glandular hairs, and Goebeler 3 shows that in Aspidium 
Sieboldi , Van Houtt, like glands occur. We may also add to 
the list Blechnum occidental , which bears resin-glands both on 
the paleae and the young leaves. Any account of the secreting 
hairs of ferns would obviously be incomplete did we not allude 
to the resin-glands which characterise such ferns as the species 
of Gymnogramme . They are of course quite homologous to 
those already described, except that the secretion appears in 
the form of numerous rods which stand out on all sides upon 
the surface of the secreting cell. The substance secreted 
appears to be partly resinous and partly waxy in character. 
They are fully described by de Bary 4 who gives the literature 
connected with them, and Goebeler also briefly alludes to them 
in the exhaustive paper to which we have already referred. 
Hairs of the Gymnogramme- type, producing their dusty- 
looking secretion in the form of resin-rods, persist even on the 
adult leaves, but the glandular hairs which we now describe 
are associated distinctly with bud-formations ; they are there- 
fore transitory in character. Whether on the leaves or paleae, 
they can only be observed in the youngest members, and here 
their secretory character is very marked, the whole apical 
portion of the young shoot being usually bathed with the 
mucilage derived from them. The hairs are very simple in 
structure, consisting either of a filament of cells all of which 
secrete (Osmunda), or occurring as stalked capitate hairs 
(Blechnum) when only the end cell is glandular. In the same 
individual both resinous and mucilaginous hairs may occur, 
but the first development of the two forms is quite similar, 
1 Schacht in Pringsheim’s Jahrb., Bd. III. 
3 Goebeler, loc. cit. 
2 De Bary, loc. cit., p. 89. 
4 De Bary, loc. cit., p. 99. 
