Notes and Brief Articles 



319 



tical fruit grower. This text contains a detailed discussion of 

 the cause of each disease so far as known so that the grower 

 will not only be able to treat the disease properly but to under- 

 stand why he is applying the remedy. So far as possible, the 

 work is based on the practical experience of the authors of the 

 book. F. J. S. 



Technical Publication 8 of the New York State College of 

 Forestry at Syracuse is a bulletin of 50 pages and 6 plates devoted 

 to a discussion of the black zones formed by wood-destroying 

 fungi. The author, Mr. A. S. Rhoads, does not claim to have 

 fully solved this problem but he gives an interesting review of 

 the literature and adds a number of results from his own in- 

 vestigations. The black zones are due to decomposition products 

 formed in the decay of the wood, which infiltrate the cell walls 

 to a greater or less extent, frequently becoming so abundant as 

 to form numerous brown drops within the cells. The formation 

 of these decomposition products is dependent mainly upon the 

 concurrence of three factors : the presence of dead cells, an 

 optimum supply of moisture, and a supply of oxygen sufficient 

 to promote oxidation. 



The Rusty-spored Agarics 



Volume 10, part 3, of North American Flora, by William A. 

 Murrill, appeared June 25, 1917. The contents of this part may 

 be indicated, as follows : 



Genera Total North American Species New Species 



Tapinia 2 



Paxillus 2 



Crepidotus 46 7 



Tubaria 14 4 



Galerula 33 8 



Naucoria 65 21 



Pluteohis. 15 4 



Mycena 12 2 



Phylloporus 1 



Gymnopilus 85 13 



Hebeloma 49 17 



324 76 



