THE FERN BULLETIN 



119 



pinnae of summer specimens being less loosely jointed 

 to the rachis. 



Of the ferns which die down in the winter, the Os- 

 111 itiuias usually lose their pinnae. It would be inter- 

 esting to note whether there are changes similar to 

 those in the leaf stems of decidous trees and shrubs 

 causing the fall of the pinnae. Pellaca afro purpurea 

 is another of the evergreen ferns but its fronds become 

 more or less brown in spots as the winter advances. 

 In Polypodium vulgare the texture of the pinnae is very 

 loose and in cold weather the fronds curl up, rachis as 

 well as pinnae becoming more or less twisted together 

 and the epidermis of the underside of the frond seems 

 to separate and is very loose and wrinkled. On the re- 

 turn of warmer weather the fronds resume their usual 

 appearance. In the spring the fronds of the previous 

 year begin to drop off. Everyone has no doubt noticed 

 that during' the winter the fronds of Asplenium mar- 

 gin ale, and A. acrostichoides lie for the most part flat 

 upon the ground. On examining a stem at the base it 

 will be seen that it is very weak and hollow except for 

 the vascular bundles running through it. I do not 

 know whether the snow breaks the stems and then al- 

 lows water and frost to hollow it or whether the stem 

 is first weakened and Vllows the frond to fall over so 

 that the snow will protect tt from too severe cold. — 

 C. E. Waters in Linnacan Fern Bulletin, Vol. _/. 



PTERIDOGRAPHIA. 



Ferns- for the House. — Not every suedes of fern 

 will endure the dry air, extremes of temperature and 

 occasional neglect that is its fate when introduced into 

 cultivation in the house, and yet those who select plants 

 for fern dishes, pot plants and the like, seldom take 

 this fact into consideration. The first fern likely to 



