1052 



SCANDINAVIAN" 1-ISHKS. 



wards, lias \ci'y thick walls, .uiil is huiiiKled fruui the 

 retral duodemiui {(hind) l)\ a strouu', aimiilar valve. 

 Just behind this vahe the u|)|ier wall (if the intestine 

 is pierced with a large hole {(i/i/i). wide enouuh tor 

 the insertion of a finger, and two somewhat smaller 

 holes, outlets of the large pancreas {pir), wliich is 

 flesh-coloured with yellowish hrown spots, and lias hien 

 formed by the coalescence oftheca'cal jivloric a])pciid- 

 ages", being therefore coursed \)\ numerous, tubular 

 l)assages (cap). This gland is of a flattened elliptical 

 shape, about 12 cm. long, H cm. broad, and 2' ,, cm. 

 thick, with sharpened edges. It is situated in the 

 circle formed b\ tiie aliove-nientitmed gyrations of the 

 intestiniform stomach: and in the ]iresent case it oc- 

 cupies rather more than two-thirds of this circle. The 

 duodenum (duod) runs back to a distance of 37 cm. 



depressions on the inside. A similar, tliough somewhat 

 finer network a])pears on the nuicous membrane linintf 

 tlie rectum (isjt). which is about .")0 cm. long.'' Here 

 we Hud an a])paratus peculiar to the Sturgeon-fishes, 

 (ianuids, Lung-fishes, and Selachians. The valve is con- 

 tinued by a spiral, in the present case with eight coils, 

 which extends almost to tlie tei'mination of the rectum. 

 The spiral consists of a thick raised margin (sji), which 

 shows the same de])ressions as the network of the mu- 

 cous membrane, though more sparsely, and which runs 

 along the inside of the upper rectal wall, being con- 

 tinuous therewith; but at eight ])oints it detaches itself 

 from the roof, and is attached instead b\- a backward 

 niendiraiious sjiiral (/y/xy;) to the rest of the intestinal 

 wall. About 2' .^ cm. before the vent the central cord 

 of the spiral terminates in a tubercular swelling (/«/<), 



ahd 



■'f^'T--'"" 



Fi.i;. 291. Vis 



f.f 



If Sliirsi-c-Mij (AcijH'iisev stnrio) 1..S4.0 iniii. Iniio. Uiken at LhIcm i.ii .Inly IStli. 1H0.T. About •' ,„ iial. sizi>. 

 Seen cbliqiiely frt'iii liclow. 

 ahd, riglit (abe. left) wall nf tlie abdominal eavily opened and folded back; apm, inner niontb of tbc loft Miillerian dnrt (M): npp, largest 

 of the pancreatic orifices visible in the opened beginning of the duodemuii (duod); cap, section of one of the pancreatic canals; diioil, duo- 

 denum; h, front part of the liver; hd, right lobe of the livery isp, spiral intestine, opened; /, spleen; M, left Miillerian duct; msp, spiral 

 membrane, the lateral membrane of the spiral valve; per, pancreas, sectioned and with one (the ventral) half somewhat raised to show the 

 canals (caj)) within it; pi/l, pylorus; sp, spira, central cord of the spinal valve; id, right, ts, left testis, with the posterior half of the latter 

 cut loose and laid back behind the left wall of the abdominal cavity; tul', tubercular swelling of the spira; u, termination of the procurvated 

 stomach; ves, dotted line indicating the outlines of the posterior imrt of the air-bladder, otherwise concealed; v/, gall-bladder; 



* — **, mesorcliial thickening of the right testis. 



from the diaphragm, where it aliruiith bends forwiird I and the extreme end of tlie rectum has five longitii- 



to a point distant about 2(»<ni. from the same, and turns ' dinal ridges with rather sharp margins on its inside, 



back with equal abruptness, soon passing iiito the straight The liver (// — lid) of the present specimen is of a bluish 



(.spiral) intestine, from which it is divided bv an an- black colour'. The left lobe is about 21 em long, the 



nular valve. Throughout the course of the duodenum i right lobe (lid) 17' „ cm. The gall-liladder (r/), about 



the mucous membrane forms a uniform network of 36 mm. long and 23 mm. broad, lies embedded in 



" Cf. their structure in the 'I'unny. see above, p. 99. 



'■ We here adopt Rathke's division of the intestinal canal. According to otlii-rs (see, for instance, WiEDERSHEiM, Grundr. Virijl. Anat. 

 Wivbelth., p. 412), the greater part of what we here call the rectum, so far .'is the spiral valve extends, should be regarded as a part of 

 the middle intestine. 



' According to Krovee it is of a ruddy yellowish brown. 



