Prof. R. Kossmann on the Ciyptoniscidaj. 15 



niscidge. Both the development of the organ from a pair of 

 cylindrical csecal tubes opening into the anterior part of the 

 intestine and its histological nature prove the homology with 

 the so-called liver. But just as I have already said with 

 regard to the Bopyrida3 that this so-called liver does not 

 function exclusively as such, but evidently performs '"' a func- 

 tion as a section of the intestine," so must I also assert deci- 

 dedly that the lumen of this so-called liver receives the food 

 of the parasite, which is identical with the blood of the host, 

 in immense quantities; that in this place this nutriment is 

 digested and absorbed, during which the organ gradually 

 shrivels up ; and that consequently the name of liver is by no 

 means physiologically applicable to the organ. But at the 

 same time it has been sufhciently demonstrated that the 

 so-called Crustacean liver is no liver at all. The name 

 reposes on an error called forth by the most insignificant 

 superficial character, namely the colour of the organ. Hoppe- 

 Seyler * and Krukenberg f found in the secretion of the 

 so-called liver of the higher Crustacea a diastatic, a peptic, 

 a tryptic, and a fat-decomposing enzyma. Max Weber \ 

 believed that he found in the epithelium of the liver, besides 

 the true hepatic cells, a second kind of cells, which he supposed 

 to fill the above more pancreatic function, and he named the 

 organ heixitopancreas. But Iloppe-Seyler showed in the 

 freshwater crayfish, and Frenzel § has lately done so in many 

 marine Crustaceans, that no biliary constituents at all are 

 present in the secretion. There are no biliary acids or their 

 soda and potash salts, no bilifuscin or the allied pigments • 

 and bilirubin was sought in vain. To this must be added 

 that Frenzel has also ascertained that Weber's assertion that 

 there are two different kinds of epithelial cells is erroneous. 

 In my Epicaridia nothing of the kind can have existed. In 

 short this organ, Avherever it has the form of a gland is 

 clearly the digestive gland of the Crustaceans, a glandula 

 intestinalis. But in the Epicaridia, and especially in the 

 Cryptoniscida3, the lumen of the intestine does not suffice for 

 the reception of the food, and then this organ takes part in it 

 in a very remarkable manner. Thus from a glandula intes- 

 tinalis it becomes an intestinum glandidare^ a reservoir 



* Hoppe-Seyler, ' Physiologische Chemie,' p. 276. 



t Krukenberg, " Vergleich.-physiol. Beitr. zur Kenntniss der Verdaii- 

 ungsvorgiiuge," and " Zur Verdauung bei den Krebsen," in Uutersucliun- 

 geu aus den physiol. lustitut in Heidelberg, 13d. ii. 



X M. Weber, " Ueber den Ban und die Thatigkeit der sog. Leber der 

 Crustaceen," in Arch. f. mikr. Anat. Bd. xvii. p. 385. 



§ J. Frenzel, " Ueber die Mitteldarmdriise der Crustaceen," in Mittlieil. 

 a. d. zool. Station zu Neapel, Bd. v. p. 50. 



