74 



mutation appeared in intensified form or in combination, and, 

 later, third, fourth and even fifth degree sports carried the in- 

 tensification of the basic variations to an apparent maximum 

 condition. Variation in the reverse direction also occurs in 

 which the progressive steps are reversed, though without the 

 production usually of sports identical with any of those progress- 

 ively developed. None of these sports produced fertile spores; 

 reproduction and probably variation occurs in runners. 



3. Spore variation in a fertile type of N. exaltata. {N. exaltata 

 fertilis). One fertile variety has been found in the Boston fern 

 series, although its exact origin is uncertain. Its spore progeny 

 comprise mainly once pinnate forms like wild exaltata, and twice 

 pinnate plants of the type of fertilis, but perhaps ten per cent 

 present new forms differing in size, leaf cutting, growth habits, 

 susceptibility to disease, etc. Most of this ten per cent of new 

 types is sterile. From several of the fertile strains second 

 generation cultures have been raised in which heredity of parent 

 characteristics is predominant but which offer still further types 

 of variants. 



4. Variation in species other than N. exaltata. At least ten 

 native species of Nephrolepis are in cultivation, especially in 

 England. Several of these species have given rise to new forms 

 under cultivation which parallel those already commented upon 

 under the topic of bud variation of the Boston fern. Some of 

 the same kinds of differences have arisen, though by spore repro- 

 duction. Of further interest is the fact that the same types of 

 variation occur in other fern genera, both in cultivation and 

 among wild plants, and the fact that many of the distinctions 

 counted as valid for the separation of species among ferns may 

 be found as bud variants in the Boston fern series. 



Adjournment followed. 



Marshall A. Howe, 



Secretary. 



Meeting of March 28, 1923 



The meeting of March 28 was held in the Museum of the 

 New York Botanical Garden, beginning at 3:30 P.M. Twenty 

 persons were present. President Richards occupied the chair. 



