172 FETCH : 



The Relation of Hypocrella to Aschersonia. 



The suggestion that Aschersonia is the pycnidial stage of 

 Hypocrella was apparently first made by Massee in an account 

 of " Hypocrella oxyspora " in the Journal of Botany (1896), 

 p. 151. His statement may be quoted verbatim : — 



" The early breaking up of the spores into their component 

 cells, and the subsequent disappearance of the asci, leaving 

 the broken -up spores free in the perithecia, led Berkeley into 

 the mistake of placing the present species in the genus Ascher- 

 sonia. In fact, I am almost certain that I have seen conidia 

 on the surface of young stromata resembhng the cells of the 

 broken-up ascospores in form in the present species. On the 

 other hand, an examination of a portion of Montague's type 

 of Aschersonia taitensis Mont., the species on which the genus 

 Aschersonia was founded, certainly has [sic) the young 

 stromata covered with a dense stratum of fusiform spores ; 

 the primordia of perithecia were also very evident in the 

 substance of the stroma, hence in all probability the genus 

 Aschersonia will prove to be nothing more than the conidial 

 form of Hypocrella ; but in the event of this being proved, 

 the name Aschersonia should be adopted for the genus, as 

 having priority over Hypocrella." 



I have not been able to trace any further observations by 

 Massee on this point, but in his Text Book of Plant Diseases 

 (1899) he wrote : " I have shown that species of Aschersonia, 

 which hitherto were only known to produce a conidial form 

 of reproduction on living leaves, produce an ascigerous 

 form of fruit, following the conidial stage, on fallen dead 

 leaves." 



Though the association of Ascherso7iia with Hypocrella is 

 undoubtedlj'- correct, the observations which Massee cited in 

 support of his theory are not accurate. ' ' Hypocrella oxyspora " 

 is an Aschersonia, as Berkeley described it, and its ascigerous 

 stage was unknown until it was recently collected in Ceylon ; 

 the conidia are not produced on the surface of the stroma, but 

 in pycnidia. In Aschersonia taitensis the conidia do not cover 

 the surface of the stroma, and the supposed primordia of the 

 perithecia are the pycnidia in which they are produced, as was 



