RT Journal Article SR Electronic T1 Paleontological and embryological development JF American Journal of Science JO Am J Sci FD American Journal of Science SP 375 OP 389 DO 10.2475/ajs.s3-20.119.375 VO s3-20 IS 119 A1 Alexander Agassiz YR 1880 UL http://www.ajsonline.org/content/s3-20/119/375.abstract AB