TAXONOMY OF THE PII.OBOLIDAE 199 



emphasised the distinction of P. crystallinus from P. Kleinii, with 

 both of which he was personally acquainted. 



Palla, after that date, issued a long account " Zur Kenntniss der 

 Pilobolus-Arten " (1900), in which he classified the known species 

 in a novel way, but without adding much to what was previously 

 discovered ; he also invented a new name, Pilobolus heterosporus 

 (Fig. 103, p. 208), which was my P. Kleinii, forma sphaerospora, 

 under a different designation. 



In the same year (1900), Morini gave a short description, without 

 a name, of a new species of Pilobolus, to which afterwards (1905) 

 Saccardo added the name P. Morinii. In 1906, Morini described 

 another species of Pilobolus, P. Borzianus, of which he also dis- 

 covered the zygospores, and in 1904 he had figured a new species 

 of Pilaira, P. Saccardiana (Fig. 110, p. 219). But Pilobolus Morinii 

 and P. Borzianus seem to be involved in a cloud of doubt, as do 

 many of the others, hke those of Spegazzini and Massee, which are 

 placed towards the end of the following systematic hsts. 



In 1926 Ling Yong, working in France, described a new species 

 of Pilaira, which he named P. Moreaui (Fig. 1 1 1, p. 220), distinguished 

 from P. anomala by its larger spores. 



The latest addition to our knowledge of the species of Pilobolus 

 has been made by Buller who, in the preceding chapter of this 

 volume, has described P. umbonatus, a new species distinguished by 

 the possession of a remarkably umbonate sporangium (Fig. 105. 

 p. 210). 



This long story of the observations made on the systematics 

 of Pilobolus during nearly two hundred and fifty years is deeply 

 interesting to the mycologist ; it shows how slowly and painfully 

 a httle 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 genus and 

 give us a comparative description of all the species that can be 

 gathered together from different parts of the world. 



Systematic Arrangement. — An attempt will now be made to 

 arrange systematically all the species of the PiloboUdae and to give 



