96 EFFECTS OF INANITION IN THE PREGNANT ALBINO RAT. 



suspended, thus allowing the blood (unmeasured) to escape. The eyeballs and brain 

 were then removed and placed in a moist chamber. The trunk was next dissected 

 and the viscera removed and weighed individually in the following sequence: 

 thyroid gland, thymus, heart (opened and blood clots removed), lungs, liver, spleen, 

 stomach and intestines (including contents, mesentery and pancreas, also weighed 

 without contents), suprarenals, kidneys, gonads, and spinal cord. 



The extremities were removed at the shoulder and hip joints and weighed. The 

 skin was next removed from the trunk and extremities and weighed; the skeleton 

 and musculature were weighed together; then the musculature was dissected off 

 and its weight determined by subtracting the weight of the skeleton from the 

 combined weight. 



As soon as possible after birth of the inanition test-rats, and immediately 

 after the removal of the prenatal controls from the mother, they were killed by 

 chloroform, if not already dead. Each was then placed upon its back and extended 

 by allowing one end of a steel ruler (300 by 35 by 2 mm., weight 263.5 grams) to rest 

 upon the abdomen and neck. In this way the amount of extension was found to be 

 much more constant than by trying to hold the body extended by means of the hand. 



The distance from the tip of the nose to the anus (nose-anus length) and from 

 the tip of the tail to the anus (tail-length) was carefully measured by calipers and 

 the distance read off on a millimeter scale. 



Jackson and Lowrey weighed the stomach, intestines, and pancreas together 

 with mesentery. In my investigation, however, the stomach, intestines, and pan- 

 creas were weighed separately. The technique was as follows: The rat was placed 

 belly down and the skin, muscles, and other tissues dissected from the left lumbar 

 region and an incision made through the peritoneum just below the costal margin. 

 By gentle pressure upon the abdomen, the stomach, spleen, and part of the pancreas 

 were forced through the opening. The spleen was now easily separated from the 

 stomach and pancreas and placed in a moist chamber. The stomach was then freed 

 from its attachments to the liver and pancreas, seized at its junction with the 

 esophagus with a small pair of forceps, firmly compressed to prevent the escape of 

 any of the gastric contents, and severed at that point and also at the pylorus. The 

 stomach was then weighed in a closed container, opened, its contents allowed to 

 escape, and the interior cleaned with moist filter paper, after which it was reweighed. 

 The intestines were removed as described by Jackson and Lowrey (1912) and 

 weighed with and without their contents, after the pancreas had been removed. 

 By subtracting the weight of the contents from the body-weight, the net body- 

 weight was obtained, and this was used as a basis for computations. 



It was found that the "gold dust" preparation, used by Jackson (1915) to tree 

 the skeleton of its periosteum and ligaments, acted too strongly upon the delicate 

 skeletons in my series, resulting in a loss of the cartilages. Consequently, the skel- 

 etons were cleaned as thoroughly as possible of muscles and ligaments merely by 

 dissection. These are designated as "moist" skeletons. The moist skeletons were 

 dried for 1 month (to a constant weight) in an oven at a temperature of 85° to 95° C. 

 to obtain their dry weight. 



