Correction

http://www.100md.com 《细胞学杂志》

     On page 3, the cover legend refers to the site of cytokinesis in a developing frog embryo, when the image in fact represents a sea urchin embryo.(Vol. 170, No. 1, July 4,)

    http://www.100md.com/html/DirDu/2007/02/17/36/94/07.htm