144 



Mycologia 



Thamnidium chaetocladioides Bref. Bot. Unters. 4: 57, 58. 1881. 

 Thamnidium Fresenii Schroet. Krypt. Fl. Schles. 3: 210. 1886. 



The branches growing from swelHngs on the principal spo- 

 rangiophores are very characteristic of the genus and the species. 

 My specimens have longer branches than the measurements given 

 in the various descriptions cited but otherwise they agree. 



Substrata : On decaying Polyporiis among other moulds. 



Specimens examined: Pennsylvania, Sumstine. 



Illustrations : Fresenius, /. c. pi. 12, f. 13-16; Van Tieghem 

 & Le Monnier, /. c. pi. 23, f. 61-63; Brefeld, /. c. pi. 2, f. 5; idem. 

 9 : pi. 2, f. 9-18; Bainier, fitude, pi. y, f. 1-7. 



2. Bulbothamnidium pulchrum variabile var. nov. 



On a piece of beef kept in a refrigerator at a temperature of 

 40° Fahr. there appeared a dense growth of mould in the autumn 

 of 1908. A careful examination failed to identify it. The 

 sporangiophores were simple, unbranched, 5-15 mm. high, white 

 to grayish white ; sporangia large, gray with a greenish hue, 

 spherical ; columella cylindrical with collarette ; spores elliptical, 

 6-12 /X, often larger in the same sporangium. The material was 

 set aside and marked new species, 



A year later the same plants growing under similar conditions 

 were again found. From this material cultures were made on 

 sterilized bread. The culture proved very perplexing; instead of 

 a simple sporangiophore, there appeared branched sporangiophores 

 as in Bulbothamnidium pulchrum. In all, sixteen cultures were 

 made and exactly the same result was obtained in each culture. 

 Ordinary beef (not sterilized) was then inoculated with spores 

 from the original plants and kept at a temperature of about 40° 

 Fahr. The simple sporangiophores were produced in these 

 cultures. 



The mode of branching, the shape and the size of sporangium, 

 columella and spores agree fairly well with Bulbothamnidium 

 pulchrum and therefore I do not feel justified at present in 

 describing it as a new species. The variability in the form of the 

 sporangiophores on different substrata and under different condi- 

 tions seems to merit a new form. 



Substrata: On beef and sterilized bread. 



