1896.] 



f 



I 



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Embryology. 



EMBRYOLOGY.^ 



The Wrinkling of Frog's Eggs During Segmentation. — 



The occurrence of wrinkles in frog's eggs during the process of seg- 

 mentation was first observed and very briefly described by Prevost and 

 l)umas, who have the honor of being the first observers of the segmenta- 

 tion itself (Annales des Sciences Naturelles, I ser., 1824, Tom II, p. 

 110). 



A somewhat better description was given later by Bar (Archiv. fiir 

 Anatomic, etc., 1837) and Reichert (the same, 1841), who gave to the 

 phenomenon the name " Faltenkranz," and made some attempt to ex- 

 plain its nature and origin. 



By far the best description, and, indeed, the only really good one 

 which has ever been published, is that by M. Schultze, which appeared 

 in 1863 (Observationes nonnullse de ovorum ranarum segmentatione, 

 Bonnge). 



He gives an excellent account of wrinkles observed in the eggs of 

 Rana temporaria and R. esculetita, and concludes with an " explanation 

 of their origin." But he really devotes only a very few lines to the 

 explanation, and gives up the remainder of this portion of his paper to 



' Edited by E. A. Andrews, Baltimore, Md., to whom abstracts reviews and 

 preliminary notes may be sent. 



