Artificial Parthenogenesis 115 



a series of papers, beginning in 1905, he showed that 

 the fertiHzed egg will live longer in hypertonic, hypo- 

 tonic, and otherwise abnormally constituted solutions 

 when the cell divisions are suppressed by lack of oxygen 

 or by the addition of KCN or of chloral hydrate. ' It 

 is thus obvious that coincident with the changes under- 

 lying nuclear division or cell division alterations occur 

 in the sensitiveness of the egg to salt solutions of ab- 

 normal concentration or constitution, e. g., NaCl+CaCla 

 isotonic with sea water, hypertonic, or hypotonic 

 solutions. 



We must, therefore, conclude that artificial mem- 

 brane formation induces development but that it 

 leaves the egg in a sickly condition in which the very 

 processes leading to cell division bring about its de- 

 struction; that if it is given time it can recover from 

 this condition and that the treatment with the hyper- 

 tonic solution also brings about this recovery rapidly 

 and reliably. 



Herlant^ suggested that the corrective effect of the 

 hypertonic solution consisted in the proper develop- 

 ment of the astrospheres required for cell division. 

 According to this author mere membrane formation 

 does not lead to the formation of sufficiently large 

 astrospheres and hence cell division may remain im- 



» Loeb, J., Arch. f. d. ges. Physiol., 1906, cxiii., 487; Biochem. Ztschr., 

 1910, xxvi., 279, 289; xxvii., 304; xxix., 80; Arch. f. Entwcklngsmech., 

 1914, xl., 322. "Herlant, M., Arch, de Biol., 1913, xxviii., 505. 



