TRANSFORMATION OF SPOROPHYLLARY. iji 



species in a meadow, it was suggested that this state resulted 

 from some injury to the sterile leaf, so that the vegetative 

 function was forced upon the very young sporophylls, causing 

 them to expand more or less, while the sporangia and sori were 

 correspondingly decreased. This suggestion met with consid- 

 erable opposition. Later the suggestion was adopted and pub- 

 lished by another, and upon this the following criticism appeared 

 in Nature, April 15, 1894 : "The remark quoted . . . about the 

 probable cause of the cases where the fronds of Onoclea have 

 an intermediate character between the usual sterile and fertile 

 conditions, is one of those sage observations which it is easy to 

 make, but which observed facts hardly or not at all sustain." 



Although an experiment had been planned for the purpose 

 of attempting to induce this form artificially by cutting off the 

 early vegetative leaves, this criticism really " set the machinery 

 in motion," for without experimental proof such an empirical 

 proposition lacked an essential foundation for argument. The 

 locality selected for carrying on the experiment was in the 

 vicinity of Ithaca, N.Y., on the flats not far from the head of 

 Cayuga Lake. The first cutting of the leaves was made May 1 1 , 

 when they were twelve to eighteen inches high. It was feared 

 at the time that the experiment had been postponed too long 

 to obtain the desired results, as it seemed within the bounds 

 of possibility that already the vegetative function might have 

 been carried on for a sufficient time for the manufacture of 

 what carbohydrates the plant would need for the perfect 

 development of the reproductive portion. The intention was 

 then to cut the leaves about once each week, in order that the 

 plants could derive very little benefit from the later developed 

 sterile leaves. Heavy rains, however, -prevented access to the 

 localities until June 9, when the leaves were cut a second time. 

 The second leaves had reached approximately the same size as 

 the first crop, and still by this time there was no sign of the 

 development of the fertile leaves, either in the experiment plat 

 or in adjacent plants which had been left as checks. 



July 12 a third visit was made to the locality on the Ithaca 

 flats, where the larger number of ferns were. Diligent search 

 at this time revealed nothing which at first could be under- 



