124 SPECIAL PHYSIOLOGY 



CO 2 . Put animal "c" into the jar, taking care to allow as little 

 loss of CO 2 as possible; close; count respirations. 



(d) Fill jar " d" full of water and displace with CO 2 . Put animal 

 "d" into jar, taking care to allow as little loss of CO 2 as possible; 

 close jar and count respirations. 



(e) Put an animal into a jar; cover the mouth of the jar with a 

 towel; insert into the jar the end of a rubber tube through which 

 illuminating gas (a mixture of CO with various other gases) may 

 be let into the jar. Let the gas in in little momentary puffs every 

 five minutes, noting the effect upon the animal. 



II. Post-mortem Examination. After an animal dies fix it to the 

 dissecting board and open the abdominal and thoracic cavities; take 

 great care not to cut a large bloodvessel; pin the flaps out so that 

 all of the organs will be exposed in place. 



4. Observations, (a) Respiration in Small Closed Space. (1) Make 

 a careful record of number of respirations and general condition of 

 animal "a" in the normal state, and at the end of every five minutes 

 after the closure of the jar. 



What changes in rate or depth of respiration have been noted? 



(2) Note all abnormal signs and symptoms. 



(3) On post-mortem examination record the condition of hea'rt, 

 large bloodvessels, lungs, liver, kidneys, and the general appearance 

 of the tissues. 



(4) Compare the conditions with those found in a normal animal, 

 prepared by the demonstrator. 



(b) Respiration in a Larger Closed Space. (5) Note all symptoms of 

 animal "b" every five minutes after confinement in the jar. 



(6) Make a post-mortem examination; record in detail the con- 

 dition of the organs as in the case of animal "a." 



(7) Compare animal "b" with normal animal. 



(8) Compare animal "b" with animal "a." 



(c) Respiration in an Atmosphere of One-third C0 2 . (9) Note all 

 symptoms at intervals of five minutes. 



(10) Compare these observations with corresponding ones from 

 animal "a" and "b." What are your conclusions? 



(11) Make a post-mortem examination; make a record as before. 



(12) Compare appearances in animal "c" with those in the 

 normal animal; with those of animal "a"; with those of animal "b." 



(13) Make a generalized statement of the facts discovered in the 

 experiments. 



(14) What is the cause of death when an animal is enclosed in a 

 small space? 



(15) What is the cause of death when an animal is enclosed in a 

 large space? 



(16) Have the relations which you have discovered any bearing 

 upon the future development of animal life upon the earth? 



