Rate of Growth and Ecesis in Lichens 



149 



growing over mosses. The Cladonia was removed as thoroughly 

 as could be done over part of the quadrat, while over the re- 

 mainder of its surface the upper half of each podetium was cut 

 off, leaving the basal portion i to 1.5 cm. long. Over the portion 

 from which the plants had been removed as completely as possible, 

 the podetia were broken into small or minute fragments and 

 worked into the mossy substratum to test the rate of regenera- 

 tion. After 4 years the plants were regenerated, and Cladonia 

 uncialis was as luxuriant as over surrounding undisturbed areas. 

 The regenerated plants were particularly luxuriant over the por- 

 tion of the quadrat on which the fragments had been worked 

 into the substratum. 



Ohio, area 10, a quadrat 10 cm. long on the third rail from the 

 top of a fence in a mesophytic wood, well shaded during the fore- 

 noon and partially shaded during the afternoon. Cladonia pityrea 

 covered the quadrat, and the podetia and as much as possible of 

 the squamules were removed that the rate of ecesis or regenera- 

 tion might be studied. After 1 year squamules had developed 

 strongly, and two minute podetia were visible to the eye, After 



3 years the quadrat showed many podetia from 3 to 5 mm. long. 

 Ohio, area 11, a quadrat 65 cm. long on the upper side of the 



second rail from the top in a fence along a roadside in a mesophy- 

 tic wood, well shaded in the forenoon and partially shaded during 

 the afternoon. All visible portions of the 3 or 4 species of 

 Cladonia which covered the quadrat were removed, leaving the 

 rotted surface of the rail. After 1 year squamules were return- 

 ing over most of the quadrat and were of sufficient size and 

 number to be seen at a distance of 3 m. After 3 years 40 podetia 

 were present in a small portion of the quadrat. These were 3 to 



4 mm. high, and most of them bore cups. 



Kentucky, area 5a, habitat like Kentucky, areas 3 and 5. The 

 thallus of Cladonia subsquamosa was taken from a quadrat 5.5 

 by 1.75 cm., leaving only such fragments as could not be removed 

 from the rock surface. After 10 months a few squamules could 

 be seen in the quadrat. After 4 years the squamules had reached 

 normal size and number, and 50 podetia were developing. After 

 8 years the podetia as well as the squamules were as numerous 

 and as large as those in surrounding undisturbed areas. 



