90 SHINKISHI HATAI 



from above downward. In the case of the rectum and large 

 intestine, it was usually necessary to cut them open in order to 

 remove the contents. The entire group of the structures above 

 named but minus contents, is here called 'alimentary tract.' 

 The removal of contents can be accomplished easily and uniformly 

 after short practice. The body weight was not corrected for 

 the contents of the alimentary tract. 



5. The suprarenal glands were carefully separated from the 

 surrounding structures. These glands are usually imbedded with- 

 in some fatty tissue but a little familiarity will enable one to 

 dissect them out without difficulty. 



6. The ovaries were carefully dissected out of the capsule. 

 The fallopian tube was not included. On account of its minute- 

 ness, the ovary is often difficult to remove when the animal is 

 young. A dissecting microscope is sometimes necessary. 



7. The kidneys: All blood vessels were cut close to the hilum 

 and any masses of fat carefully removed. 



All these organs having been removed and placed in weighing 

 bottles, the thoracic cavity was next opened along the median 

 ventral line by a cut extending as far as the upper end of the 

 neck. Care was taken not to injure the thyroid gland, which 

 lies close to the trachea. 



8. Thymus gland: Large lymphatic glands together with fat 

 lie close to this organ but were not included. Because the 

 weight of this gland is so closely correlated with age, the data 

 already obtained will not be presented at this time but reserved 

 until the study of an extended series of animals of known age 

 has been completed. 



9. The heart was removed by cutting all the vessels close to 

 their proximal ends. The heart was next cut open by longitudi- 

 nal slits and any blood clots carefully removed. 



\0. The lungs were severed from the trachea. The esophagus 

 which lies near to the lungs must be removed. The infected 

 lungs of rats suffering from so-called 'pneumonia' are more or 

 less filled with pus. Such lungs were weighed as removed but 

 these data were not used in computing the formula for lung weight. 



