664 JOTTINGS FROM SYDNEY UNIVERSITY BIOLOGICAL LABORATORY, 



The greater part of the interior is in most parts of the body- 

 occupied by the form of connective tissue characteristic of Flat- 

 worms and commonly called parenchyma — a faintly granular 

 uncolourable matrix having running through it felt-like bundles of 

 very delicate fibres with stellate, angular or rounded nuclei here 

 and there. Occasional cavities and channels occur in this gi^ound- 

 tissue. Embedded in it, especially in its outer part, are great num- 

 bers of the calcareous corptiscles (cal), so characteristic of Cestodes. 

 These are rounded bodies which for the most part show a distinc- 

 tion into a central nucleus and an outer rind. The central part 

 consists of a (usually) rounded body of strongly refracting ap]iear- 

 auce and perfectly homogeneous ; while the outer part, which does 

 not refract the light so strongly, is composed of several concentric 

 layers. These bodies dissolve and nearly or completely disappear 

 under the action of strong acids, but without effervescence. Caustic 

 potash only renders the outer part clearer. From their appearance 

 when acted on by dilute acid, it would appear that the two jiarts 

 of the corpuscle are of different composition — the inner part 

 becoming before it is entirely dissolved converted into a cluster 

 of granules while the outer part never becomes granular, but 

 only gradually becomes less and less distinct till a fine outline 

 alone remains. 



Separated from the epidermal layer by an interval of paien- 

 chyma with calcareous corpuscles is a zone of longitudinally- 

 arranged muscular fibres (l.m.), divided into parallel bundles by 

 intervals of parenchyma and parenchyma muscle. These are 

 slender, elongated, nucleated fibres. A transverse or circular 

 layer of muscle is entirely wanting. 



Running through the parenchyma are numerous bundles of the 

 very slender muscular fibres of the parenchyma (p.m.). Most of 

 those are nearly at right angles to the surface, though many are 

 oblique ; as they approach the surface the fibres separate out from 

 one another and divide to become attached in the manner already 

 described. 



Though a nervous system can be detected, it is very indistinct. 

 In the head portion of the body a number of fibres having exactly 



