temperature of reptiles with weak respiration is 1.8 to 5.4 

 F. above the circumambient medium, and for others the fol- 

 lowing degrees have been given : 



Temperature Authority 



Turtles . . 33.6 F. 38 



Chameleon 1.8 F. (above air) 38 



Lizards 1.3 to 14.6 F. (above air) 38 



Vipers 4 to 11.3 F. (above air) 38 



Boa (incubating) 10.8 F. (above air) 38 



Snake (incubating) ..50.0 to 53.6 F. 118 



Viper 68.0 F. (air being 58.0 F.) 156 



Python 76.0 F. (air being 60.0 F.) 156 



Turtle 84.0 F. (air being 79.0 F.) 156 



The fact that the male boa, which does not incubate, 

 has a lower temperature than the female (156) is worth 

 noting. 



There is shown in the figures just given (see Table 

 No. 7) enough tendency for the temperatures to rise as the 

 species gets "higher" in its life scale to give color to the pos- 

 sibility that with reptiles, as with birds, the temperatures 

 and the species become elevated concomitantly. From the 

 "swiftness of life" point of view, it is interesting, and per- 

 haps important, to note that the quiet, sluggish reptiles have 

 lower temperatures than do the active ones. 



A relationship between reptiles and birds, should, and 

 does, leave in both, traces of a common ancestry; can one 

 find indications of this in the incubation periods of birds? 

 If the length of incubation in birds be, as I am convinced it 

 it, a deep-rooted, inelastic and inherited characteristic, it 

 should exhibit some proto-reptile or some proto-reptile-bird 

 peculiarity or peculiarities; the data show, both with birds 

 and reptiles a decided tendency to arrange themselves in 

 groups of periods having a septenate multiple, i. e., 14, 21, 

 28, 42 and 56 days. This septenate tendency has been ex- 

 plained on the hypothesis that it is an inheritance from 

 ancestors which were aquatic, and subject to, and probably 

 modified by, maximal tides every twenty-eight days. If this 

 be true, it would bespeak an amazing tenacity in the persist- 

 ence in birds, of this very ancient character. It may not, 

 however, be a correct explanation, because the same sep- 

 tenate or monthly spacings are to be found attached to the 

 functions of mammals, i. e., gestation and rut. It does not 

 seem possible that such an old influence should have left an 

 impress which is visible in a stem so far removed from the 

 main trunk as is that of the mammal branch. 



Taxonomy, the "Ascent Theory" and the Data 

 I know full well that real and apparent inconsistencies 

 and conflicts will be found in the correlation of these three, 



70 



