ARTIFICIAL PARTHENOGENESIS 575 



salt solutions used to cause eggs to develop, presumably preventing the 

 increase in permeability usually caused by the salt solution. 



The use of fish eggs in settling this question presented itself to the 

 writer. It was found that the eggs of the pike will develop in distilled 

 water and are practically impermeable to salts — that is to say, that 

 the salts which they contain difEuse out of them only in such small 

 quantities as to render detection almost impossible even with as sensi- 

 tive an instrument as the nephelometer. It was found, further, that 

 pure solutions of sodium nitrate increased the permeability of the eggs 

 to chlorides (since the chlorides diffused rapidly from the eggs). The 

 use of anesthetics prevented the effect of nitrates on the permeability 

 of the eggs, so that the chlorides failed to diffuse.'' 



It is thus evident that the problem of parthenogenesis is closely 

 interwoven with fundamental problems of physiology — stimulation, 

 oxidation and anesthesia; and that the final elucidation of partheno- 

 genesis and fertilization must wait on the solution of these other prob- 

 lems. On the other hand, the systematic study of parthenogenesis has 

 already shed much light on general physiology, and progress will be 

 more certain if all of these problems be kept before the mind of the 

 investigator. 



T ScieTK^e, 1914, Vol. 40, p. 214. 



