IT is generally acknowledged that land-living plants have sprung from some algal source: that the land was invaded and that the invaders show form and structure adapted to sub-aerial life. If this be ...

All vertebrate embryos follow a common developmental path due to their common ancestry. All have a set of very similar genes (the homeobox genes) that define their basic body plan. As they grow, the ...

"With 2057 drawings and photographs, grouped as 380 illustrations." SCDIRB copy 39088019622893 not included in the Bibliotheca Beckwithiana (unpublished). SCDIRB copy has bookplate: Smithsonian ...

THIS text-book by two Virginian embryologists has served a useful purpose in the past and will continue to do so in the future. It deals more particularly with human development, and the comparative ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...