95 



to show signs of life. There was considerahle variation in the 

 results obtained, but not more than might be expected on account 

 of differences of climate in the various localities, the nature of 

 the season, the health and vigor of the individual plants dealt 

 with, etc. It would take too much time and space to go into the 

 details of these experiments, but the results of one of them, which 

 was continued for more than a vear, are so interesting that a brief 

 outline of it is given here. 



On December 30, 1913, a large mat of polypodium (about 25 x 

 48 cm.) was gathered from a rocky hillside near Rome. Ga., 

 where it was growing in a thick substratum of moss on one of 

 the numerous outcroppings of shale and slate that form the ribs 

 of the hill. The strata are tilted in such a way that the edge of 

 the laminae is for the most part turned upward, and the mould 

 which collects in the crevices ofifers a convenient foothold where 

 the polypodium and the prostrate cactus {Opuutia humifusa 

 Raf.) are found in close proximity to each other. The fern, 

 with its substratum of moss, peeled off from the rock entire, like 

 the skin of a banana, and was transferred to a flat stone in the 

 basement of my house. The weather being warm and rainy, the 

 fronds were all fully expanded and in fine condition, and it was 

 not until January 13, 1914, that they began to show signs of 

 withering. By January 31. the substratum had become dry and 

 the fronds were all withered. On April 11, May 17, and June 

 15, specimens detached from the mat with their substratum, and 

 exposed in the rain, revised in each case, within from 12 to 24 

 hours. 



On July 30, the remainder of the mat was removed from the 

 basement to the drier atmosphere upstairs and left on top of a 

 bookcase in my study. October 30 (95 days after removal from 

 the basement) another specimen was put out in a warm mist at 

 8 P.M., without watering the substratum, and by the same hour 

 next morning it had revived sufficiently to show that it was still 

 alive'. The same specimen was then placed in water, and after 

 12 hours more, the fronds were all expanded but looked weak 

 and sickly. ( Xote : The best specimens had all been used up, 



