AUTHOR'S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, FEBRUARY 16 
EXPERIMENTS ON THE PHYSIOLOGY OF DIGESTION 
IN THE BLATTIDAE 
ELDON W. SANFORD 
Osborn Zoological Laboratory, Yale University, New Haven, Conn. 
TWENTY-ONE FIGURES 
INTRODUCTION 
The following experiments were undertaken to explain certain 
phases of digestion in cockroaches, and especially the processes 
concerned in digestion of fat, as well as other related problems. 
The subject is not a new one; many investigators have studied 
various phases of the problem, but they have in several cases 
arrived at very different conclusions, One of these workers was 
Prof. Alexander Petrunkevitch (’00), who suggested the problem 
to me.! 
The real object of my investigation has been to attack the 
problem from a new point of view, besides repeating to a greater 
or less degree the experiments of previous workers. I have en- 
deavored to amplify considerably the scope of previous work 
through the use of newer stains and the physiological and ex- 
perimental methods. 
The main problems which I hoped to investigate and elucidate 
were concerned with the rdle of the crop in digesting and ab- 
1 Prof. Petrunkevitch’s paper appeared in 1900, and since then several inves- 
tigators have come to results distinctly at variance with his. This disagreement 
is explained in part by the fact that Professor Petrunkevitch gave almost no 
data concerning the details of his experiments. Most of the data were lost in 
consequence of political disturbances, and without the data the work could not 
be defended. Moreover, lack of these data prevented repetition and verification 
of the experiments. After many trials I arrived at methods of experimentation 
which tended to verify Petrunkevitch’s results, and to explain the disagreement 
of other authors. From this beginning I proceeded to further and more varied 
experiments, always using groups of animals in each experiment. More than six 
hundred cockroaches were used in all. 
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