462 RESEARCHES ON FUNGI 



Chapter IV. — This Chapter contains a systematic account and arrange- 

 ment of the Pilobohdae, contributed by W. B. Grove, and it may be 

 considered as a revision of the systematic part of his Monograph of the 

 Pilobolidae pubhshed in 1884. 



A history of our knowledge of the taxonomy of the PiloboHdae during 

 nearly two hundred and fifty years is recorded. It shows how slowly 

 and painfully a little accurate knowledge has been accumulated. From 

 now on, with the modern technique of pure cultures and the art of photo- 

 graphy at our disposal, progress should be more rapid. It is to be hoped 

 that some younger mycologist may be stimulated by this presentation 

 of the subject to make a life- study of the Pilobolidae and give us a com- 

 parative description of all the species that can be gathered together from 

 different parts of the world. 



The first observations on a Pilobolus, made by John Banister in 

 Virginia, were recorded by Ray in 1688. The most recently found species, 

 Pilobolus umbonatus, is described by Buller in this volume (1934). 



An attempt has been made to arrange systematically all the known 

 species of the Pilobolidae and to give to the group itself and to the two 

 genera, Pilobolus and Pilaira, included within it, more precise definitions 

 than have yet appeared. 



Sixteen species of Pilobolus and five species of Pilaira are Usted and 

 described. 



Of the species of Pilobolus the following are considered to have 

 been adequately described and illustrated : crystallinus, heterosporus, 

 Kleinii, longipes, nanus, oedipus, roridus, sphaerosporus, and umbonatus ; 

 while the following are considered to have been insufficiently or negli- 

 gently described : argentinus, Borzianus, minutus, Morinii, pullus, roseus, 

 and Schmidtii. 



A key to the species of Pilobolus is presented. It is based on char- 

 acters of the sporangium, the trophocyst, and the spores. 



The five known species of Pilaira are the following : anomala, dimidi- 

 ata, Moreaui, nigrescens, and Saccardiana. A key to these species is also 

 provided. 



Appended is a bibliography which includes all those papers and books 

 which refer more particularly to the species of Pilobolidae and their 

 differentiation. Some additional works which treat of the physiology, 

 ecology, and other aspects of the group are cited in the preceding Chapters 

 written by Buller. 



PART II 



Chapter I. — Most Discomycetes exhibit the phenomenon of puffing, i.e. 

 when they are subjected to certain changed conditions they pass from a 

 quiescent to an active state and suddenly liberate a cloud of spores, visible 

 to the naked eye. The fruit-bodies of Hymenomycetes, on the other 



