Vol. 7. No- 5. 



TORREYA 



May, 1907 



THE RATE AND PERIOD OF GROWTH OF POLY- 

 PORUS LUCIDUS * 



By C. \V. Edgerton 



Very little has been done by botanists in regard to rate and 

 period of growth among members of the higher groups of fungi. 

 Miss Douglas (2) in 1906 studied the growth oi Panaeohis reti- 

 nigis, one of the agarics, under greenhouse conditions. Schmitz 

 (4) in 1842 worked on a number of forms, both agarics and 

 Polypori. Fries (3) had made the statement that fungi grow 

 from the center outwards. Schmitz took exception to this, and 

 by marking spaces of known size on such forms as Polystictiis 

 hirsiitus and others, he was able to show that the growth was in 

 the periphery and not the center. Beyond these, the literature 

 relating to the growth of the higher fungi is very scanty. 



It was to find out as much as possible concerning the phe- 

 nomena of growth in these forms, especially the woody members, 

 that this study was undertaken. Little was known definitely 

 concerning the rate of growth, the growing period, the effects of 

 external conditions, or for that matter even the actual position of 

 the growing area. In some perennial forms, such as Fovies foinen- 

 tarhis and others in which a layer is added each year, it is an easy 

 matter to obtain the yearly increase. But in these, the growth 

 is so slow that it is impossible to obtain reliable data on the other 

 points just mentioned. A form growing in abundance around 

 Ithaca, N. Y., that seemed to be very well adapted for such a 

 study was the so-called Poly poms hicidus (Leys.) Fr.f Its 



* Contribution from the Department of Botany, Cornell University, No. 120. 



f This is the name by which the fungus is commonly known in this country. 

 f^^ However it has recently been described by Dr. Murrill in Bull. Torrey Club 29 : 

 ^^ 601. 1902, as a new species, Ganoderina Tsiigae. 

 T— [No. 4, Vol. 7, of ToRREYA, comprising pages 69-88, was issued April 15, 1907.] 



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