is explained on the basis of Williams* (1923,192^A,B) and Buxton's 

 (1932,1933) exposition of the comparatively high humidity in sand, 

 cracks of walls, and soil in areas that are otherwise dry, Brett's 

 discussion and the comparison of his findings with those of Cvm- 

 liffe and of other workers, especially those of Robinson (19A2C ) 

 discussed on p. 137, which corroborate those of Brett, should be 

 stvidied for their practical importance by anyone concerned with 

 0. moubata. Since only careful and thorough research in the field 

 as well as in the laboratory can conclusively settle the matter, 

 a more complete discussion of this question is hardly in order here. 



Structure and Function 



Introduction 



No thorough studies of the internal anatomy and histology of 

 0. moubata have been undertaken. VJhat has been done on certain 

 aspects of these subjects is reviewed in the following paragraphs. 

 On the whole, workers have been content to accept Christophers' 

 (1906) careful though still somewhat general description of the 

 internal anatomy of 0. savignyi as also applicable to 0. moubata . 

 Recently, Biirgdorf er~ (1951 jl has provided a short account of the 

 internal anatomy of 0, moubata and some of his excellent illustra- 

 tions are reproduced" (Figures 56 to 58). However, 0. moubata 

 deserves more specialized attention than it has thu's far been 

 accorded. These two species differ in habits, habitats, distri- 

 bution, ajid receptivity to pathogenic organisms. It may be ex- 

 pected, therefore, that under their leathery shells, which also 

 differ, significant anatomical and physiological differences re- 

 main to be demonstrated. 



Internal Anatomy 



The general features of the internal anatomy of these two 

 species are similar and Christophers' (loc. cit .) description of 

 a dissection of 0, savignyi, as presented below, applies eqtially 

 well to 0. moubata (with known differences noted): 



"'Over the whole dorsiom lies a fine membranous ex- 

 pansion of tracheae and trabeciilae of the fat body. 

 Ikying in this, in the median line, is the delicate 

 tubular heart. Posteriorly, at about the junction of 



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