ALBINO RAT VISCERA, GLANDS, EYEBALLS: WEIGHTS 91 



Associated with the infected lung a pathological condition of 

 the alimentaiy tract is usually found. The tract is diminished in 

 weight. 



11. Thyroid gland: The removal of the thyroid is rather diffi- 

 cult on account of the minute muscles, similar in coloration to 

 the gland, which adhere very closely to it. A little experience 

 enables one to avoid this difficulty. 



This completes the list of viscera removed by the ventral 

 incisions. 



The animal was now turned with the dorsal side up, an inci- 

 sion made along median dorsal line, from the root of the tail to 

 the tip of the nose, and the skin laid back on each side. 



12. The eyeballs were removed free from all the muscles. 



13. The vertebral canal was then opened and the spinal cord 

 removed, free from the spinal nerves, which were severed at the 

 point of their emergence from the cord. The cord was separated 

 from the brain at the tip of calamus scriptorius, equivalent to 

 the level of the first spinal nerve. 



14. The brain: Care was taken not to injure the olfactoiy 

 bulbs or the flocculus; the latter is embedded in a bony capsule. 



15. The hypophysis was removed last. Removal of this organ 

 is very simple in the rat as it can be lifted from the floor of the 

 cranium with a fine forceps without further dissection. Both 

 the glandular and infundibular portions were included. 



For weighing, these fifteen organs were placed as removed 

 in four closed bottles. Bottle 1 contained liver, spleen, kidneys, 

 testes, heart and lungs. Bottle 2 contained alimentary tract, 

 ovaries, suprarenals, thymus, thyroid, eyeballs and hypophysis. 

 Bottle 3 contained brain. Bottle 4 contained spinal cord. 



In each instance the bottle with all the organs in it was first 

 weighed, then the organs were successively removed, one at a 

 time, and the bottle reweighed after each removal. The emptied 

 bottle with such small quantities of fluid as drained from the 

 organs was finally weighed, and from these data the weight of 

 each viscus was computed. It is seen from this that each organ 

 was weighed with its contained blood. The weighings were all 

 made on delicate balances to one-tenth of a milligram. 



