Abstract
This chapter discusses the corticle and subcorticle cytoplasm of the Lymnaea egg. The cortex carries a great deal of the spatial information required for building an amphibian embryo, mapping out each part of the embryo. The main features of the cortical field are laid down at the eight-cell stage. The cortex in the uncleaved fertilized egg may be pictured as containing only a morphogenetic factor centered in one place, the grey crescent. At some time between the first and third cleavages, this acts as a center initiating and activating the establishment of a cortical field. The cortex also plays an important part in the development of cephalopods. Constriction and ultraviolet microbeam experiments indicate that there is a morphogenetic pattern located in the superficial layer, at least from first cleavage up to an early blastoderm stage. Excision or injury of the cortex leads to specific localized organ deficiencies. Regulation is possible only within an organ field, not between fields.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
