ABNORMALITIES IN CESTODE MONIEZIA. I 5 I 



f, g, there is a partial duplication of the reproductive organs, but 

 no furrow between the two sets. Here the causes leading to 

 localization of growth have not affected the outer parts of the 

 body. The genital organs are always reduced in cases of this kind. 



Furthermore, it is possible that the furrow may not coincide 

 perfectly with the boundaries of the proglottid in the central pa- 

 renchyma. The growth in the peripheral parenchyma may be 

 reduced or modified in such a manner as to change the direction 

 of the furrow so that it no longer indicates the exact boundary. 

 A very distinct case of this kind was shown in Fig. 38, Part II., 

 at ;;/, and discussed on page 280, and it is possible that the ob- 

 lique furrow between c and d in Fig. 38 is another case (p. 

 283, Part II.). 



It is probable that in many cases furrows which curve anter- 

 iorly or posteriorly do not correspond to the exact boundaries of 

 the proglottids. Curved furrows of this kind always indicate 

 incomplete development in the peripheral parenchyma, but the 

 central regions may often be more perfectly developed than the 

 furrows indicate. 



The preceding discussion of a few typical cases of form-varia- 

 tion in the proglottids renders it sufficiently evident that all of 

 these variations are due to incomplete development of some part 

 or parts, or of the whole proglottid. One of the two anlagen 

 may be absent or may become united with the next anterior or 

 posterior to it. Either or both may fail to attain full size or 

 normal form. 



The inter-proglottidal furrows are the chief external indications 

 of internal conditions of growth and development. But the 

 structure of the genital organs in some of the imperfect proglottids 

 indicates a somewhat more nearly perfect condition than that 

 represented by the furrows. 



Throughout the whole series of form-variations no new 

 methods of growth or proglottid-formation are indicated. All 

 variations absorbed are simply failures to attain full development. 

 They illustrate very clearly the independent development of each 

 of the two anlagen. 



Variations in the form of the proglottids abnormalities are 

 extremelv common in Moniezia, much more so than in most 



