JACQUES LOEB 



541 



six chromosomes in a number of specimens. The question arises how 

 to account for the fact that the number of chromosomes is diploid. 

 The first thought might be that the eggs had been accidentally fer- 

 tihzed, but this is excluded by the mode of procedure. As is well 

 known, the eggs of the frog are fertihzed outside the body of the 





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Fig. 2. Ovaries and kidneys of a parthenogenetic female frog. 



female, and the females used for our experiments had not yet com- 

 menced to lay their eggs. The females after having been killed were 

 submersed in 95 per cent alcohol and left there for several minutes 

 to kill any sperm that might have stuck to the outside skin. The 

 skin was cut open and the eggs were removed from the oviduct with 



