Nr. l] ANATOMICAL ST UDIES ON ANELASMA ÅND SCALPEL LIM 23 



the muscle fibres is observed; the muscle tissues degenerate, and 

 are to a great degree replaced by a rich development of connective 

 tissue, which, however, gives a pathologic impression (textfig. V). 

 A dosser study at once reveals degenerative features in the tissue, 

 the nuclei (pl. V, fig. 29) exhibiting the picture of chromatolysis. 

 Also the erythrocytes of the shark degenerate rather numerously 

 round the offshoots of the parasite (pl. V, fig. 31); they attain an 

 irregular shape, and seem to be dissolved. A similar picture is 

 afforded by the leucocytes (pl. V, fig. 30). — As is well known it is 

 a general rule that the attack of a piarasitic organism is answered 

 in the host by an inf lux of leucocytes to the pilace of attaok. We 

 should thus also in Etmopterus expect a larger ainount of leucocy- 

 tes in the degenerating tissues, or near them. As a matter of 

 fact, several leucocytes are observed in the parts conoerned, but 

 their number was nevertheless astonishingly small. This must be 

 due to the rapid dissolution of the shark' s tissues in the envkons of 

 the filaments of the parasite. This dissolution clearly appiears from 

 the mentioned signs of degeneration which predominate in the 

 tissues of Etmopterus round the filaments of Anelasma. We have 

 here a sure proof that Anelasma also absorbs nutriment from the 

 body of the shark through the filaments of its peduncle. 



The absorbtion of food through the filaments has of course set its 

 mark upon the digestive organs of Anelasma. Even though the 

 digestive organs proper according to their high organisation cannot 

 be judged as unimportant in the animal' s life, their finer structure 

 seems to evince a rather reduced function. The investigation of the 

 fullgrown specimens has in all cases denionstrated intestinal cells in 

 rest, and also the digestive glands consist of cells which exhibit an 

 indifferent if not directly degenerated appearance. If we moreover 

 compare the muscle s of the alimentary canal in Anelasma with 

 those of Scalpellum, we find that especiailly the proctodæum of 

 Anelasma is strikingly sparsely endowed with muscles; this also 

 speaks in favour of the suppiosition of a subordinate irnportance of 

 the alimientary canal as a digestive organ. It is at present impos- 

 sible to give a definitive answer as to the part played by the 

 intestine in the life hi story of the fullgrown Anelasma; we have 

 nevertheless reaison to believe that its maintenance, or hetter, its 

 rather high development, is due to its importance as an excretory 

 organ. Even though indisputable renal organs are found in the 

 proboscoidal part of the animal, they cannot make an excretory 

 intestinal organ superfluous. 



Turning again to the filamentary appendages of the peduncle, 

 we have to answer the question, where do the supposed dissolving 

 secretions originate, which influence the tissues of the host? The 

 tissues of the filaments themselves contain no gland cells, and the 



