80 HUXLEY, ON DYSTERIA. 



wards^ and terminates in the substance of the body without 

 any apparent connection with other parts. 



The whole apparatus is moveable. The posterior portion 

 is pushed against the anterior, and the heads of the styles 

 come into contact with the posterior convex edges of the 

 supero-lateral pieces, and push them forwards ; the posterior 

 portion is then retracted, and the whole apparatus returns 

 to its previous arrangement. 



In one Dysteria, which had swallowed a filament of Oscil- 

 latoria, so long, that the one extremity projected from the 

 mouth, when the other was as far back in the body as it 

 could go, these movements took place as many as twenty 

 times in a minute. 



Mr. Dyster further informs me that, in one of these ani- 

 mals which he saw feed, the frond of Oscillatoria was rather 

 " swum upon " than seized, ingestion being accomplished by 

 a smooth gliding motion, apparently without displacement 

 of the styles ; but that when the act was completed the styles 

 " gave a kind of snap and moved slightly forwards." 



Mr. Dyster is inclined to think that the Oscillatoria passed 

 through the anterior ring-like portion of the apparatus. I 

 have not seen the animal feed, but on structural grounds I 

 should rather have been inclined to place the oral aperture 

 at {a, fig. 13,) and to suppose that the food would pass above 

 the anterior ring. The apparatus is destroyed by caustic 

 potash, but remains unaltered on the addition of acetic 

 acid; it is therefore, probably, entirely composed of animal 

 matter. 



Immediately above the annular portion of the apparatus, 

 there is invariably present a remarkable amethyst-coloured 

 globule [t) , apparently composed of a homogeneous fluid. It 

 has on an average a diameter of -^ o'o o ii^ch, and it is entirely 

 lodged in the more convex portion of the body."^ In many 

 specimens no other colouring matter than this can be 

 detected, but in some, minute granules (^^^Joo inch) of a 

 similar colour are scattered through the body. What con- 

 nection these have with the large constant globule is not 

 clear, since, although the dimensions of the latter vary 

 from the size given above to one fourth or less, no relation 

 could be observed between this diminution and the presence 

 of the granules in other parts of the body. 



Behind the amethystine glol)ulc the substance of the body 

 has the appearance, common to the Infusoria generally, of a 



* In one or two specimens a minute ametliystine globule, not more tlmu 

 oue sixtli tlie d iameter of the large one, was visible immediately below and 

 behind it. Acetic acid destroys the colouring matter. 



