DrPFEEENTIATION OF THE PROTOZOA. 367 



lelation existing between tlie primarily ingested food in AmoebcB 

 and the so-called crystalline bodies underlying the ectosare, and 

 have suggested that they may be the insoluble residue of the 

 animal's prey. Some observations (as yet unpublished) of my 

 friend Mr. Bernard on the digestive cells of the blood-sucking 

 Arachnids have stroogly confirmed this view, and it seems 

 probable that these refractive dots are the last residuum of the 

 animal's food, and that as such they make their way out along the 

 lines of the enclosing membrane. 



I have hitherto made no allusion to any relation existing between 

 the condensations I have described beneath the external rugae and 

 Haeckel's myophan srriation, simply because the more closely I 

 sought after it the more distant any such relationship appeared ; 

 in fact these structures appear to be rather complementary or 

 antagonistic than homologous. As Haeckel describes them, the 

 myophan striations " erscheinen als ein System von regelmassigen, 



parallelen, fiuen Streifen dicht gedrangt neben einander 



verlaufen, und abwechselnd heller und dunkler erscheinen " * ; and 

 according to this author, these structures lie at the base of his 

 ciliary or second layer, and themselves constitute the third layer ■\. 

 Now the condensations I have described are embedded in the 

 ciliary layer itself, and are immediately below the not very distinct 

 outer cuticle. In somewhat tangential sections the myophan striae 

 are seen to correspond exactly with the ditches between the super- 

 ficial ridges, a fact pointed out by Entz % ; while the denser rods 

 described above are situated immediately beneath the apices of 

 these ridges, and they consequently alternate with the myophan 

 stripes. Thin sections do not demonstrate the existence of such 

 contractile fibres forming a third layer, and the homogeneous cha- 

 racter of the condensations to which I have drawn attention seem 

 to suggest elastic, in contradistinction to contractile function, and 

 to shift the responsibility of the latter on to the ciliary layer as a 

 whole. It may here be remarked that this view would bring the 

 contractility of the ciliate Infusoria into much closer harmony 

 with that of the Ehizopods. 



Since describing the cross section of the oral furrow and the 

 comparatively large skeletal structure which lies beneath it, I 



* ' Jenaische Zeitschrift fiir Medecin,' Bd. vii. p. 535. 



t Greeff considers them as hollow structures and speaks of the " Lumina der 

 Muakelfasern." 



\ 'Zeitschrift fiir wissenschaft. Zoologie,' jcxjviii. p. 167. 



