282 THE ANATOMY OF CESTODES. 



generally spheroidal, but often elliptical or kidney-like shape. In 

 their solidity, in their power of refraction, and above all in their more 



or less distinct concentric lamination, they 

 {^ 0^ f\ r®^ remind one of starch grains. Sometimes 



/^ »Z >^ the central mass is distinguishable like a 



M_M'C^\ >-it^3-' nucleus from the surrounding substance, 

 -'' ^^ which is occasionally radiately arranged. 



Fig. 145. — Calcareous cor- In some cases the bodies form twins, with 

 aTrst^rsTzr-^^'two or three centres and an irregular 



form. 

 Very varied opinions have been held as to the nature of these 

 calcareous bodies since they were first described by Pallas and Goze. 

 In the bladder-worms, where they often occur in most extraordinary 

 abundance, they were frequently regarded as eggs, or as blood and 

 lymph corpuscles. It was only after the lapse of some time that 

 Doy^re and others proved that they were mainly composed of car- 

 bonate of lime. This altered the nature of the current explanations, 

 •and V. Siebold, reasoning on the analogy of similar bodies in the lower 

 animals, claimed them as skeletal, while Claparede thought they were 

 the results of an execretion. ^ This opinion was based on an observa- 

 tion made in the first instance on a Trematode-larva, but which seemed 

 to shed a new light on the nature of these bodies in the Cestodes. 

 Claparede thought he had clearly established that these structures 

 were not freely embedded in the body-parenchyma, but were sur- 

 rounded by pouch-like dilatations of the terminal branches of the 

 excretory system. Although I formerly believed myself wa,rranted 

 in confirming these conclusions from an investigation of an oceanic 

 Cestode^ (the Echinohothrium of the ray), which I conducted along 

 with Pagenstecher, and indeed attempted in the first edition of this 

 work to support the above theory, and to remove the physiological 

 arguments against it, yet I feel myself now compelled, along with 

 other investigators (Eindfleisch, Landois and Sommer, Schiefferdecker), 

 to adopt V. Siebold's opinion. I must, however, leave it undecided 

 whether these bodies have any other functional significance than as 

 supporting or protective structures. 



It would, however, be a mistake to suppose that the designation 

 " calcareous bodies " implied that these structures were wholly com- 

 posed of lime. In the tape- worms they do indeed contain in many 

 cases a very large proportion of lime» — 21 per cent, of salts (mostly 



1 Zeitschr.f. wiss. Zool., Bd. ix., p. 99, 1858. 



- " Untersuchungen tiber niedere Seethiere," Millle7''s Archiv f. Anat. u, Physiol., 

 p. 605, 1858. 



" There are, besides, /H?^}i,■aSflfl*j|}/^fl!^fo?H6i'^^'fl?^ o^'ide of iron, soda, and putash. 



