X PREFACE 



stands," may be true philosophy, but it is certainly an open question 

 how that rule shall be applied. If an author recognized and defined 

 a given species in times past, and, in accordance with views then 

 held, assigned the species to a particular genus, common honesty, it 

 would seem, would require that his work be recognized. To assume 

 that any later writer who may choose to set to familiar genera limits 

 unknown before shall thereby be empowered to write all species so 

 displaced his own, as if, forsooth, now for the first time in the history 

 of science published or described, is not only absolutely and in- 

 excusably misleading, but actually increases by just so much the 

 amount of debris with which the taxonomy of the subject is already 

 cumbered. 



In face of a work so painstaking and voluminous as that of 

 Rostafinski, and in view of the almost universal confusion that pre- 

 ceded him, it would seem idle to change for reasons purely technical 

 the nomenclature which the Polish author has established. Especially 

 is this true in the case of organisms so very perishable and fragile as 

 those now in question where comparative revision is apt to result in 

 uncertainty. We had preferred to leave the Rostafinskian, i. e. the 

 heretofore current nomenclature, untouched ; but since other writers 

 have preferred to do otherwise, we are compelled to recognize the 

 resultant confusion. 



Slime-moulds have long attracted the attention of the student of 

 nature. For nearly two hundred years they find place more or less 

 definite in botanical literature. Micheli, 1729, figures a number of 

 them, some so accurately that the identity of the species is hardly to 

 be questioned. Other early writers are Buxbaum and Dillenius. 

 But the great names before Rostafinski are Schrader, Persoon, and 

 Fries. Schrader's judgment was especially clear. In his Nova 

 Genera, 1797, he recognizes plainly the difference between slime- 

 moulds and everything else that passed by the name of fungus, and 

 proposed that they should be set off in a family by themselves,^ but 

 he suggested no definite name. Nees (C. G.) also made the same 

 observation in 1817, and proposed the name Mrogastres; but he 

 cites as type of his aerogastres, Eurotium, and includes so many 



^ Schrader, Nova Plantarum Genera, 1797, pp. vi-vii. 



