456 PBTCH : 



More serious objections can be urged against the subgenera 

 Chcetodiplodia and Lasiodiplodia. A Ghcetodiplodia is a pilose 

 simple Diplodia. while a Lasiodiplodia is a pilose Botryo- 

 diplodia. But it Diplodia cacaoicola, i.e., Botryodiplodia 

 theohromcE in its simple form, is grown on a cacao pod in a 

 damp chamber, it becomes a Chcetodiplodia, wliile if the 

 Botryodiplodia form is grown under equivalent conditions it 

 becomes Lasiodiplodia, as in Brick's specimens. From the 

 example afforded by Botryodiplodia theobromce, it is evident 

 that Chcetodiplodia and Lasiodiplodia are based on characters 

 which are due to environmental factors, either growth in a 

 more or less saturated atmosphere or on a substratum 

 amply provided witli moisture. They ought therefore to be 

 discarded, Chcetodiplodia being thrown into Diplodia and 

 Lasiodiplodia into Botryodiplodia, the latter subgenus being 

 amended as suggested. On the same grounds, Rhynchodiplodia 

 should presumably be referred to Pellionella. Nothing would 

 be lost by this sacrifice, since species of these supposed 

 subgenera are only rarely recognizable as such. Chcetodi- 

 plodia might be retained for those species, if any there be, 

 which bear true setae on the pycnidium wall. 



Van Hall and Drost (18) have already arrived at similar 

 conclusions. They state " as the hairlike processes of the 

 pycnidia {i.e., of Botryodiplodia theobromce), the characteristic 

 by which Chcetodiplodia is distinguished from Diplodia, is 

 not constant but results from definite conditions, the genus 

 Chcetodiplodia must be annulled and joined to the genus 

 Diplodia." " Sometimes in diseased branches or pods the 

 pycnidia appear in groups, sometimes they stand isolated. As 

 this appearance in groups, the distinguisliing character of the 

 genus Lasiodiplodia, is not constant, the genus Lasiodiplodia 

 must also be cancelled and joined to the genus Diplodia." 

 The adoption of Van Hall and Drost's suggestion would 

 involve the abandonment of the subgenus Botryodiplodia 

 also. There is much in favour of such a course, since, without 

 a large quantity of material, a Botryodiplodia, as at present 

 understood, is not always recognizable. This is quite evident 

 from the records of Botryodiplodia theobromce. But it would 

 seem preferable to refer Lasiodiplodia to Botryodiplodia, and 



