626 
PHYSIOLOGY: A. G. MAYER 
Mendelian machinery at work evident. Unwelcome as these conclu- 
sions may sound to obscurantists and to those in general who have an 
antipathy for exact modes of procedure, the necessity for such refined 
methods here should be obvious. In particular, it will be desirable to 
examine more intensively those cases which show the characteristics 
described in Section 5 for balanced lethal factors. 
1 The full account of this case will appear subsequently, and also an account, by Alten- 
burg and Muller, of the truncate case. 
2 Sturtevant also had performed certain linkage experiments in which beaded was pres- 
ent; these showed that it was well on the other side of sooty from pink. 
^ Since the above has gone to press, a case in Campanula which may be due to bal- 
anced lethals has been reported by Miss Pellew in the Journal of Genetics. 
IS DEATH FROM HIGH TEMPERATURE DUE TO THE ACCUMU- 
LATION OF ACID IN THE TISSUES? 
By Alfred Goldsborough Mayer 
DEPARTMENT OF MARINE BIOLOGY. CARNEGIE INSTITUTION OF WASHINGTON 
Communicated September 12. 1917 
1 find that there is a converse relation between the rate of oxygen 
consumption in reef corals and their ability to resist high temperature, 
those corals which are most readily killed by heat having the highest 
metabolism (rate of oxygen consumption). 
NAME OF CORAL 
CONSTANT TEMPERATURE 
EXPOSURE TO WHICH CAUSES 
DEATH IN ONE HOUR 
RELATIVE RATE OF OXYGEN 
CONSUMPTION PER GRAM 
OF LIVING SUBSTANCE IN 
EACH CORAL 
Acropora muricata. . 
Orbicella annularis. . 
Maeandra areola ta. , 
Fa via fragum 
Siderastrea radians. 
34.7 
35.60 
36.80 
37 . 05 
38.20 
18.7 
6.1 
5.5 
3.8 
1.0* 
* At 28.5°C. 1 gram of living substance of Siderastrea radians consumes 0.0256 cc. of 
oxygen per hour. The oxygen being measured at 0°C. and 760 mm. pressure. 
Also, if sea water be super-saturated with carbon dioxide gas, the 
toxic effect is in the same sequence as that of high temperature. That is 
to say, those corals which are readily killed by heat are also correspond- 
ingly easily killed by H2CO3. 
This toxic effect of carbon dioxide is not due to its replacing some 
of the oxygen of the sea water, for I find that corals are remarkably 
insensitive to a reduction in the oxygen supply, all species except 
Acropora living more than eleven hours in sea water under an air pump 
which reduced the oxygen to less than 5% of that of normal sea water ; 
and even Acropora can withstand six hours of this treatment. 
