190 NATURAL HISTORY BULLETIN. 



Magnus has used the term "adaptive-races," meaning 

 parasitic fungi which for several generations have become 

 habituated to a particular host plant, and therefore more 

 easily infect that species than another upon which the 

 same parasitic fungus also occurs. Klebahn says: 

 (translated) "I would speak of biological races, when 

 among fungi that are morphologically similar, yet infect a 

 series of host plants, there are those that infect one host 

 easily and abundantly, and another host with diffi- 

 culty and sparingly, and also others that, conversely, infect 

 the latter readily and the former with difficulty, and still 

 others that infect all equally. The totality of these fungi 

 would form the species, the last being the typical form of 

 it and the first two biological races. From this it will be 

 seen that Puccinia smilacearum-digraphidis and Puccinia 

 convallarics-digraphidis as they have shown themselves in 

 my experiments, are to be regarded as biological species." 



The following forms on Phalaris having teleutospores 

 nearly or quite identical, but having secidia on different 

 species of hosts, have been described: 



1. Puccinia phalaridis Plow. 1888. Jour. Linn. Soc. 

 — :88. Infects only Arum maculatum . 



2. Puccinia zvinteriana Magn. 1894. Hedw. 33:83. (P. 

 sessilis Schneider, as used by Winter, Plowright, and 

 Klebahn). Infects only Allium ursinum. 



3. Puccinia smilacearum-digraphidis Klebahn. 1896. 

 Zeits. f. Pflkr. 6:261. (P. sessilis Schneider as used by 

 Magnus and Dietel). Infects Polygonatum, Majanthcmum 

 Convallaria and Paris. 



4. Puccinia convallarics-digrapliidis Klebahn. 1896. 

 1. c. {P. digraphidis Sopp.) Infects only Convallaria. 



5. Puccinia paridis-digraphidis Klebahn. 1896. 1. c. 

 (P. paridis Plow.). Infects only Paris. 



6. Puccinia schmidtiana Dietel. 1896. Ber. d. Naturf. 



