1912.] The Size of the Trachea in Warm- Blooded Animals. 61 



Table V. — Ptarmigan (individuals). 





Sex. 



Body weight. 



Radius of trachea. 



Area of tracheal cross- 

 section. 



|| 



Tracheal cross-section 

 as percentage of body- 

 weight. 



T3 



© 



d 



§ * O 



£ R ■* 



J, • 



# II 



1 ?* 



en 

 g 



Difference between 

 cross-section calcu- 

 lated and observed. 



Cross-section calc ul a ( ed 

 as percentage (2 "16) 

 of body weight. 



Difference between 

 cross-section calcu- 

 lated and observed. 







grms. 



mm. 



sq. mm. 









per cent. 





per cent. 



l 



? 



460 



1 -81 



10 -33 



/ D 



2 25 



in -tA 



1U o* 



1 -99 



9 94 



3 92 



2 



? 



470 



1 -84 



10-58 



7 -48 



2-25 



10-61 



0-28 



10 -14 



4-34 



3 



? 



500 



1 -81 



10 -33 



7-98 



2 06 



11 09 



6 -85 



10 -8 



4-35 



4 



? 



530 



1-97 



12 -25 



7 05 



2-31 



11 -59 



5 -74 



11 43 



7 17 



5 



? 



538 



1 96 



12 12 



7 15 



2 -27 



11 -62 



4 3 



11 62 



4-3 



5 



? 



553 



1 -95 



11 -98 



7 -38 



2-17 



11 88 



84 



11 94 



0-34 



7 



? 



590 



2 01 



12 -63 



7 33 



2 -14 



12 -42 



1 -69 



12-73 



-79 



8 



? 



600 



1 99 



12 -44 



7 53 



2 -08 



12 -59 



1 19 



12 96 



4 01 



9 



9 



630 



2 04 



13 03 



7 46 



2 07 



13 05 



15 



13 -6 



4 19 



10 



? 



710 



2 11 



14 



7 53 



197 



14 -16 



113 



15-23 



8 62 





7-45 



2 16 





2 42 





4 2 



tracheal constant show no periodicity, but the tracheal percentage decreases 

 steadily, although not regularly, from 2'25 in the lightest, to 1*97 in the 

 heaviest animal. When the tracheal area (T) is calculated by our formula 

 the average deviation of the observed from the calculated values is 2-42 per 

 cent., while it is 4 - 2 per cent, (nearly twice as great) if the area be 

 calculated in per cent, of body weight. If the value of n be taken as 

 - 70 k becomes 7'0, and if n be - 72 k is 7"93. 



Table VI. — Ptarmigan (grouped). 



Group. 



Numbers of individuals 

 from Table V in 

 group. 



Average body weight. 



Average radius of 

 trachea. 



"3 



'a 

 d 

 ~ 



O ~ 

 d o 



g us 

 s ? 



5Q 



i£ i 



d 71 



- o 



<u S 

 > a 



h 



II 



Tracheal cross-section 

 as percentage of body- 

 weight. 



a > j> 



Si ' 

 O 11 -Si 



T- EH V 



CO 



QQ 

 O 



6 



Difference between 

 cross-section calcu- 

 lated and observed. 



Cross-section calculated 

 as percentage (2 -15) 

 of body weight. 



c - 



-_ L. ■ 



•° 3 

 - -= 



_o 



o y = 

 y ~ 



? ir* 



— r. ^ 







grin. 



mm. 



sq. mm. 









per cent. 





per cent. 



A 



1-2 



465 



1 -83 



10 -46 



7 "5 



2 25 



10 -53 



0-66 



10 -o 



4-6 



B 



3-4 



515 



1 -89 



11 -29 



7-46 



2 19 



11 -32 



0-27 



11 07 



1 99 



C 



5-6 



547 



1 -96 



12 -05 



7 3 



2 2 



11 -81 



2 -03 



11 -76 



2-47 



D 



7-8 



595 



2-0 



12 -54 



7 -44 



2 -11 



12-54 



o-o 



12 -79 



1 95 



E 



9-10 



670 



2-08 



13 -52 



7 51 



2 02 



13 64 



0-88 



14-41 



6 18 





7-44 



2-15 





77 





3 44 



