CONCLUSION 



In the foregoing pages are described 285 species of the Myce- 

 tozoa, regarded as valid, and reported from North America. Of 

 these, 269 are represented by specimens from North America in 

 the Herbarium of the New York Botanical Garden, and of the 

 latter 216 were personally studied and collected in the field from 

 North Carolina to Lake St. John, in Quebec, with one or two 

 exceptions, but often from many localities. All but three of the 

 remaining species described are represented by specimens from 

 other parts of the world. Numerous forms proposed and de- 

 scribed as species by other students are treated synonymously or 

 omitted. Rarely have they been found otherwise than by the 

 original collector, and often many years ago. The great majority 

 are based on abnormal, cold or wet weather, locational or seasonal 

 forms, known to exist in many recognized species; trifling de- 

 partures from typical characters, usual in nearly all species; im- 

 perfect observations and conceptions of characters with conse- 

 quent incorrect descriptions; forms based merely on size, although 

 size is not generally recognized as a distinguishing specific charac- 

 ter; intermediate forms with a combination of minor characters 

 of two related and known species; trifling difi^erences, no more 

 than varietal; limeless phases of calcareous forms; and forms of 

 other groups proposed as species of the Mycetozoa. Proposed 

 species of this nature indicate that the authors had insufficient 

 field knowledge of the conditions affecting the development of the 

 fruiting bodies, and lacked enough specimens from wide areas in 

 order to understand thoroughly the great variation known to 

 exist. 



The entire number of species throughout the world is 318, 

 regarded here as valid. There may be a few more among those 

 described in recent years, but world conditions make it impossible 

 to obtain authentic material for examination. A list is appended 

 of the Zdt additional species. Those preceded by an asterisk are 

 in the Herbarium of the New York Botanical Garden, and 

 double asterisks indicate the specimen is type or authentic 

 material. 



273 



