160 



Mundaabning, paa Midtpartiet af Hovedet, med en sæk- 

 formig Udvidning (Svælget), der er omtrent 4 Mm. lang 

 og 3 Mm. bred, bliver derefter meget smal, omtr. 1 Mm., 

 igjennem den lange småle Brystdel, indtil den kommer 

 ned imod dennes tykkere Parti, hvor den atter udvider 

 sig meget betydeligt (Maven); saa at den her i en Længde 

 af 46 Mm. har en Tykkelse af omtrent 3 Mm. Fra Ab- 

 dominaldelens Begyndelse bliver den igjen smal, omtr. 

 1,5 Mm. (Tarm) og aftager nu i Tykkelse, til den aabner 

 sig i Anus. Tarmrøret bestaar af en yderst tynd Mem- 

 bran, som er den før beskrevne Peritonealhinde, en Mu- 

 skelhud, der dannes af to Lag stærke Muskler, nemlig 

 Bingmusklerne, det ydre, og Længdemusklerne, det indre 

 Lag. Disse Lag ere saaledes ordnede, at Tarmrøret un- 

 der en svag Forstørrelse i Mikroskopet har et gittret 

 Udseende. Saavel fra King- som Længdemusklerne ud- 

 gaa enkelte Fibre, der anastomosere med Sidebundterne. 

 Indenfor Muskelhuden findes især paa Tarmrørets tyk- 

 kere Del et Lag, der indeholder en Mængde aflange, for- 

 grenede Legemer, som have et temmelig mørkegult, kor- 

 net Indhold. Paa Spiserøret ere disse Legemer yderst 

 sparsomme, hvorimod her iagttages andre rundagtige Le- 

 gemer, ganske svarende til de af Claus benævnte Tarm- 

 celler, der ere fyldte med fine, glindsende Korn. Tarm- 

 rørets indre Flade er overalt forsynet med et kjernerigt 

 Celle-Epithel. Hele Tarmrøret har et lige Løb efter Dy- 

 rets Længde, er fæstet ved en Mængde tynde Muskelfibre 

 til den af os tidligere beskrevne indre Membran af Hu- 

 den, — dets bagerste Flade bidrager til at danne Bun- 

 den af den lange Kygkanal. 



Generationsorganerne bestaa af Æggestokke med de- 

 res Udførsel skanal, Cementkjertlerne med deres Udfør- 

 selsgang, Æggetraadene og endelig to korte Kanaler. 



Æggestokkene, der have sit Leie en paa hver Side 

 af Tarmrøret, just der hvor dette udvider sig i Bryst- 

 delen, dog nærmere Rygfladen, — have en flad og lang- 

 strakt Figur, "ere 8 Mm. lange, 2,5 Mm. brede. De be- 

 staa af et temmelig smalt Rør, der begynder med en blind 

 Ende og danner en Mængde paa hinanden liggende Slyng- 

 ninger, som ere forenede ved et temmelig fast Bindevæv. 

 Dette Rør er paa hele den indre Flade beklædt med et 

 kjernerigt Celle-Epithel og fyldt med Æggeceller. Paa 

 den øverste Ende af Æggestokkene sees Røret at antage 

 en Korktrækkerform, idet det her gaar over i Oviducten. 

 Denne er næsten cylinder-rund, har en Længde af 45 Mm. 

 og en Tykkelse af 1 Mm., og ender lige ved Abdominal- 

 delens Begyndelse, hvor den fortsætter sig i Ægge- 

 traadene. 



Saavel Æggestokkene som Oviducten ere beklædte 

 af Peritonealhinden. Ifølge vore Observationer ere vi til- 

 bøielige til at samstemme med Professor Claus deri, at 



previously noticed, in the middle part of the head, with 

 a sack-like enlargement (the gullet) which is about 4 Mm. 

 long and 3 Mm. broad, becoming then very narrow about 

 1 Mm. through the long narrow thoracic part, until it 

 comes down towards the thicker part of the thoracic 

 region, where it again widens very considerably (the 

 stomach); so that it has here, for a length of 46 Mm. a 

 thickness of about 3 Mm. From the commencement of 

 the abdominal part, it becomes again narrow, about 1 5 

 Mm. (intestine), and diminishes now in thickness, until it 

 opens into the anus. The intestinal canal consists of an 

 extremely thin membrane, which is the peritoneal mem- 

 brane previously described, a muscular skin formed of 

 two layers of strong muscles, namely the annular muscles 

 forming the exterior layer, and the longitudinal muscles the 

 interior. These layers are so arranged as to give to the 

 intestinal canal a latticed appearance, when it is seen 

 slightly magnified, through a microscope. From the 

 longitudinal muscles, as well as from the annular muscles, 

 there proceed single fibres, which anastomose with the 

 lateral fascicles. Within the muscular skin, there is found, 

 especially on the thicker part of the intestinal canal, a 

 layer containing a number of oblong ramified bodiesj 

 which have a rather darkish yellow content. On the 

 oesophagus these bodies are extremely sparse; while here 

 we observe other roundish bodies corresponding entirely 

 to those called by Claus intestinal cells, which are filled 

 with minute shining granules. The inner surface of the 

 intestinal canal is everywhere provided with a nucleus- 

 like cell-epithelium. The whole intestinal canal has a 

 straight course along the length of the animal; it is 

 attached by a number of thin muscular fibres to the 

 inner membrane of the skin previously described by us; 

 its posterior surface contributes to form the bottom of 

 the long dorsal canal. 



The organs of generation consist of ovaries with 

 their excretion-canal; cement-glands with their excretions- 

 canals, ovisacs; and finally two short canals. 



The ovaries, which have their situation, one on each side 

 of the intestinal canal, precisely where the latter expands 

 itself in the thoracic part, and nearer to the dorsal sur- 

 face, have a flat and elongated figure; they are 8 Mm. 

 long, and 2,5 Mm. broad. They consist of a rather 

 narrow tube, which commences with a closed extremity, 

 and forms a number of superincumbent circumvolutions 

 united by a rather solid connecting tissue. This tube is, 

 on the whole of its interior surface, lined with a cell- 

 epithelium abounding in nuclei and filled with egg-cells. 

 On the upper extremity of the ovaries, the tube is seen 

 to assume a cork-screw form, going over here into the 

 oviduct. The latter is nearly cylindrical; it has a length 

 of 45 Mm. and a thickness of 1 Mm., and terminates just 

 at the commencement of the abdominal part, where it is 

 continued in the ovisacs. 



The ovaries, as well as the oviduct, are covered by 

 the peritoneal membrane. According to our observations, 

 we are inclined to agree with Professor Claus, that the 



