NECTURUS 



Necturus or Menobranchus, commonly called the mud-puppy, 

 is distributed through the Mississippi and St. Lawrence basins, 

 from whence it has found its way in recent years into other 

 waters (the Hudson at Albany, etc.). Where it occurs it may 

 be taken with hook and line, but it is better to capture it with 

 nets or seines, on account of its habit of swallowing the hook. 



Two specimens, a male and a female, besides a prepared 

 skeleton, will be required by each student. One of the specimens, 

 preferably the male, should be injected. The injection is best 

 accomplished in the following order: First, with blue, inject 

 forwards and backwards through the hepatic vein at the base of 

 the liver, filling the heart, postcava, and the branches in the 

 liver. Next, with red, into the dorsal aorta in both directions 

 at about the middle of the ccelom. The postcava being already 

 filled with blue, the aorta is more readily seen. Lastly insert the 

 canula into the portal vein just before its entrance into the liver, 

 and inject with blue forwards and backwards. 



The preparation of the skeleton is a more difficult matter 

 than with some animals, especially in the caudal region. Skele- 

 tons good enough for study purposes may be made by boiling with 

 soap solution, following this by picking away the flesh with the 

 forceps and finishing by careful brushing with a tooth-brush. 

 The boiling should not be too prolonged because of the danger 

 of separation of the parts. When not in use the skeletons should 

 be kept in alcohol, but when studied they should be soaked in 

 water, which swells the cartilages and restores them to their 

 normal condition. The female specimen can be used for skeletal 

 purposes after the urogenitals have been studied. 



