form, although there had not been any change whatever in its 

 surroundings. Now what caused this plant to deviate from its 

 normal habit one season and return to it another under conditions 

 exactly the same in both seasons, and where there was no pre- 

 ceptible outside disturbance to interrupt or interfere in any way 

 with its free growth ? 3d. I had in one season found sixty 

 specimens of obtusilobata in various stages of development, in 

 one locality, on plants, some of which had been injured in various 

 ways, and some of which were well supplied with healthy sterile 

 fronds, while the next season I was unable to find a single speci- 

 men there, although I searched diligently, and found plenty of 

 plants injured as before, the locality being one that was exposed 

 to all sorts of accidents. 4th. During the seasons of 1873-74, I 

 made a series of experiments for the purpose of ascertaining, if 

 possible, how far injuries to the plants might go toward the obtu- 

 silobata forms. These experiments were begun as early as May, 

 and continued at intervals of a fortnight, up to the first of Sep- 

 tember. During that time some hundreds of plants in different 

 localities were mutilated in every conceivable manner, but no 

 obtusilobata was obtained in any instance. These experiments 

 were continued during the next season (1875) with the same un- 

 favorable result, while late in August, 1881, I found three speci- 

 mens of obtusilobata on plants with well matured, uninjured 

 sterile fronds, and the appearance of the plants indicated that 

 they had not been disturbed since they first started to grow in 

 the spring. 



My conclusion, from those and other facts given, was that 

 " the variation was due to some cause within the plant, rather 

 than to any outside influence however much such influence might 

 assist in developing an impulse already existing." It will be seen 

 from these data which I have quoted that my experiments ante- 

 date the recent experiments of Prof. Geo. F. Atkinson by nearly 

 twenty-five years. Now I have the greatest admiration for Prof. 

 Atkinson's work, which is of the very highest order and value, 

 and I know that the experiments which he has published an ac- 

 count of must be correct, and justify the deduction which he has 

 made from them. But I do not think he could have known of 

 these published experiments of my own, or he would have taken 

 them into consideration, and modified his conclusion in the same 

 direction that I have mine, at least so far as to see that while ob- 

 tusilobata may sometimes follow mutilation of plants, it does not 



