322 



is a part ot the bordered region in a plane and, in this entire region, possesses its own 

 relative position determined by its relations with other surrounding subregions." (p.251). 

 The relationships between sclerites and subregions are characterised on p.251: (A) 

 Principally a single sclerite (often inclusive of the surrounding membrane) corresponds 

 with a single subregion. (B) A single sclerite can spread over two or more subregions, 

 or two or more subregions can participate in a single sclerite. (C) A subregion can be 

 completely membranous. 



- They do not explicitly say whether (B) and (C) are exclusively regarded as derived 

 states, or if they can be already realised in the hypothetical ground-plan of Blattaria. 

 However, the definition of the subregions makes sense only if the demarcation of 

 "smallest indivisible units" obeys a uniform principle - and this can only be the 

 possession of an own sclerite according to (A). Hence, I interpret Mizukubo & 

 Hirashima in the following way: A set of 11 subregions on each side, each subregion 

 with one sclerite of its own, is regarded as the ground-plan pattern of Blattaria. 

 (According to (A); (B) and (C) realised in derived states only.) 



- They deduce the basic pattern of 11 subregions per side from the morphology of the 

 various Blattinae: By considering several Blattinae and by combining their features, the 

 dividing of the phallomere complex into subregions can be accomplished in a way that 

 the relative positions of the subregions of the left side are a mirror-image of the relative 

 positions of the subregions of the right side. 



- In both Blattella and Opisthoplatia the dividing into subregions can be accompHshed 

 in a way that the subregions of the left side as well as those of the right side have the 

 same relative positions as they have in Blattinae and in the hypothetical basic pattern. 

 In their dividing procedure the authors assume losses or fusions for some sclerites 

 (according to (B) and (C)). 



- From these equal relative positions of the subregions they deduce homology relations 

 between the subregions of the left and of the right side of the phallomere complex as 

 well as between the subregions of the phallomeres of different species. Side-homologous 

 subregions get the same names - except for L (left) or R (right) in the first position. 



- Concerning the closeness of the relations between neighboring subregions, they 

 distinguish four categories which describe the closeness or intensity of the mutual 

 relations between the respective sclerites: weak adjacency - adjacency - articulation - 

 fusion. All the relations between all neighboring subregions together are the association 

 pattern of the phallomere complex. 



- They investigate the muscle insertions on the various subregions. 



- In their homology analysis the authors largely neglect the musculature. If the course of 

 a muscle is consistent with the homology assumptions deduced from the relative 

 positions of the subregions, this is regarded as a confirmation. If there is inconsistency, 

 the authors do not regard this as a matter of conflict. 



The statements of Mizukubo & Hirashima include, or result in, the following assumptions 

 regarding the ground-plan of Blattaria: 



- The left as well as the right side of the phallomere complex are provided with (exactly) 

 11 separate sclerites. (This results from the definition and characterisation of 

 "subregion", compare above). 



