Fern {Aspidium Sp. or Pteris 8p.) 



Material. — Ferns are almost everywhere abundant in 

 woods, meadows, and along the roadside, edges of fields, 

 etc. Some specimens should be taken in the early- 

 spring as the fronds are coming out of the soil, others 

 in the early summer when the vegetative fronds are 

 mature, and still others later in the summer and in the 

 early fall, when the spores are to be found in different 

 stages of formation. Prothallia are to be looked for on 

 mossy logs and rooks and on the soil at the base of the 

 fern plant. Some of the specimens should be pressed 

 as for an herbarium, and others preserved in alcohol. 

 Species closely related to, or even identical with, our 

 wild forms are to be had at almost all greenhouses, and 

 are available in midwinter. Their prothallia are usually 

 abundant on the soil of the neighboring flower-pots and 

 beds, or adhering to the surface of the flower-pots them- 

 selves, particularly of those which are covered with a 

 film of vegetable growths. Wild ferns may be kept 

 in a greenhouse if wanted for examination in winter. 

 Their prothallia may be raised from spores strewn upon 

 the surface of clean, damp sand. The cultures should 

 be examined every few days, and the different stages of 

 development studied as they become available. The 

 young fern plants will develop from the prothallia in 

 about six or eight weeks. The prothallia may be picked 

 off the surface of the sand with needles and examined 

 in a drop of water. They may be preserved by being 



