688 
BOTANY: A. R. C. HAAS 
illustrates the general truth that we, like the birds, have but a very 
limited power of altering the ebb and flow of our behavior cycles. Cycli- 
cal recurrence does not prove that human behavior consists of mere chain 
reflexes, neither does it prove that the instinctive behavior of birds con- 
sists of mere chain reflexes. 
Doctor Raymond Pearl read a preliminary draft of this paper and 
suggested important improvements, for which I express my thanks. 
The article of which this is an abstract will appear in the Biological 
Bulletin. 
^ Herrick, C. J., Introduction to Neurology, 1915, (61). 
^ Thomdike, E. L., The Original Nature of Man. 
2 Ellis, H., Studies in the Psychology of Sex. III. Analysis of the Sexual Impulse. 
* Hirn, Y., The Origins of Art. 
RAPID RESPIRATION AFTER DEATH 
By A. R. C. Haas 
LABORATORY OF PLANT PHYSIOLOGY, HARVARD UNIVERSITY 
Communicated by G. H. Parker, October 20, 1 91 7 
Various observers^ have reported that respiration may continue after 
death but apparently the rapidity of post mortem respiration does not 
in any of these cases exceed the normal rate. It is therefore of interest 
to find that the marine alga Laminaria in the presence of certain reagents 
may respire more rapidly after death than in its normal state. 
In my experiments the rate of respiration was determined by measuring 
the output of CO2 (at 16°C.) by means of suitable indicators added to the 
solution which had been rendered acid by the respiration of the Lami- 
naria. The method has been previously described.^ 
As soon as a determination of the respiration had been made, the so- 
lution bathing the tissue was renewed and after exposure for the same 
length of time the amount of respiration was again determined. In this 
manner the respiration of the material could be followed and it could be 
seen whether it was approximately constant before the beginning of an 
experiment. This constancy was obtained in all the experiments here 
recorded. 
In some cases (acetone 17.4% and alcohol 24.2%) the killing agent 
extracted from the plant a small amount of pigment which interfered 
with the color of the indicator.^ But this difficulty disappeared after 
the first two periods, as was shown by running pure hydrogen through 
the solution, after which it returned to the color found in normal sea 
water plus indicator. This method also showed conclusively that the 
acid excreted by the plant was CO2 and not an organic acid. 
