THE WOOD FERNS. 145 



the disposition of certain specimens. Generally speak- 

 ing, it may be said that the variety intermedium is 

 rather longer, narrower and more finely cut than the 

 type, with the under surface minutely glandular. The 

 young fronds are frequently so sticky from these glands 

 that they adhere 

 to the paper when 

 pressed for the her- 

 barium. It is our 

 commonest f o r m i \ \\ ,\ 

 and is abundant in \ ^ 

 nearly all moist 

 woods. The vari- 

 ety dilatatum is an 

 upland or moun- A PINNULE. Much enlarged. 



tain form, at least in the southern part of its range. It 

 is more inclined to be ovate and the inferior pinnules 

 on the lowest pair of pinnae are conspicuously elongated. 

 The principal points that are depended upon for separat- 

 ing the forms may be contrasted as follows : 



In true spinulosum the scales of the stipe are pale brown, 

 the blade ovate-lanceolate, the pinnae oblique to the 

 rachis and the indusium glabrous. 



In the variety intermedium the scales of the stipe are 

 brown with a darker centre, the blades oblong-ovate, 

 often rather narrow, the pinnae spreading, the indusium 

 ragged edged and dotted with stalked glands. 



In the variety dilatatum the scales of the stipe are 

 larger, brown with a dark centre, the blade broadly 

 ovate, the lower pinnules much lengthened and the 

 indusium glabrous. 



It may be noted in passing that in Great Britain where 

 dilatatum is common, and frequently regarded as a dis- 



