THE CHRISTMAS AND HOLLY FERNS. ITI 
nules, the holly fern was once believed to be an immature 
form of this species or of the closely allied, P. aculeatum. 
According to Dodge’s “ Ferns and Fern Allies of New 
England,” this species is common along the mountain 
brooks of northern New England. In Canadait is found 
sparingly in the Provinces of New Brunswick, Nova Sco- 
tia and Quebec. Southward it ranges to the mountains of 
Pennsylvania, having been collected at several localities in 
that State. Itis also found in Michigan. In the West 
it is replaced by the true P. aculeatum as wellas by the 
varieties Californicum and angulare. 
The genus Polystichum as now defined contains about 
thirty species, pretty generally distributed throughout 
the world. The name is derived from two Greek words 
signifying many rows. It is difficultto understand its 
application here unless it refers to the rows of sporangia. 
