Investigations into tlie conditions governing tlie temperature of the body. 43 



or towards the morning, the minimum in the day-time. They also 

 found the average for night birds to be a little lower than that for 

 day birds. Only very few of the owls have a well-marked period, and 

 the time for the maximum varies greatly, following the time when 

 the bird is hunting. These researches go to show, therefore, the 

 very same as the researches on the monkeys; in both cases the 

 result is, that the form of the curve of temperature is determined 

 by the mode of life of the animals. 



Osborne ^ has recently had the good idea of examining whether 

 the temperature curve was changed during a journey from Melbourne 

 to London. The difference of longitude between the two places 

 being about 10 hours, the temperature curve, if following steadily 

 the Melbourne time, must become reversed in London. Osborne 

 found that his maximum temperature, which occurred at 6 p.m. in 

 Melbourne, followed the local time; but as the transition was gradual 

 he did not venture to base anything on his results. 



It follows from the statements above that a day and night 

 curve of typical form for the mouth temperature is out of the 

 question. Hørmann^ has indeed measured the temperature of the 

 mouth and found curves very similar in appearance to curves for 

 the rectal temperature; but his measurements were made under 

 special conditions. Hørmann first says that it is well-known that 

 the temperature in the mouth does not differ much from "die des 

 Kerns"; in himself the difference was 025° С (in the morning, in 

 bed: rectum 36-35°, mouth 361°). Such a determination is naturally 

 not satisfactory. Hørmann has quite overlooked all difficulties in 

 the mouth measurements; he has unconsciously concealed the in- 

 fluence of the outer temperature on the daily variations, and has 

 included this influence in the relation between the curves for day 

 and night. Just as for the rectal temperature he thus found higher 

 temperatures in the day, lower in the night; but very different 

 causes have produced this uniformity and he has not given these 

 causes due consideration. 



Oehler^ has shown for the skin temperature that the varia- 

 tions run parallel with the changes which take place at the same 

 time in the rectal temperature, but they are in still better agreement 

 with the curves for the air temperature. This dependency becomes 

 specially evident whenever a sudden fall in the temperature of the 

 room is caused by ventilation; a sharp fall in all the curves for 



1 Proceedings of tlie Pliysiol. Society. Jan. 25. 1908. Tlie Journal of Physiol, Vol. 



XXXVI, (i, 1908. 

 ■^ Zeitschrift f. Biologie, Bd. 36, 1898. 

 3 1. с. 



