16 ARrriFicIAL PARTHENOGENESIS AND FERTILIZATION 
treatment with the hypertonic solution or with the temporary 
suppression. of oxidations. 
Ten years ago the writer found that the life of the untreated 
unfertilized egg can be prolonged for some time (though not 
indefinitely) by suppressing the oxidations in the egg. This 
indicated that the oxidations in the unfertilized egg are one of 
the causes which lead to the premature death of the unfertilized 
egg. This conclusion is supported by the fact that the mature 
unfertilized egg of the starfish dies much more quickly than the 
unfertilized egg of the sea-urchin; the rate of oxidations in the 
mature but unfertilized egg of the starfish is comparatively much 
greater than in the mature but unfertilized egg of the sea-urchin. 
We must therefore conclude that the oxidations going on in 
the mature but unfertilized egg are one of the causes that lead 
directly or indirectly to its death; and that in the light of this 
fact it appears as if the process of fertilization rendered the egg 
immune against oxidations, or, in other words, transformed 
the egg from an anaerobe into an aerobe. 
10. Since physiologists who are not familiar with the litera- 
ture often state that artificial parthenogenesis does not lead to 
the production of larvae capable of development, it might be 
well to point out that such statements are contrary to fact. 
Delage has raised two parthenogenetic larvae of the sea-urchin 
during sixteen months to the stage of sexual maturity... Both 
were males. Loeb and Bancroft raised a parthenogenetic frog 
through metamorphosis and found that its sex glands econ- 
tained eggs.? If the raising of larvae were not such a tedious 
process, parthenogenetic animals would exist today in large 
numbers, since parthenogenetic larvae may be normal and 
apparently healthy. 
1 Delage, Compt. rend. Acad. d. Sc., CXLVIII, 453, 1909. 
2 Loeb and Bancroft, Jour. Exper. Zool., XIV, 275, 1913. 
