Description
Sequential cross sections of a 33-hour chick embryo mounted in rows on microscope slides. A developing brain and heart, an increasing number of somites, and a diminishing primitive streak are outstanding characteristics of this age.
Serial microscope slides are prepared to show sequential cross-sectional views of an entire specimen, from head to tail. The sections are mounted in rows in consecutive order on the same slide. Depending on the size of the specimen and the thickness of the section, multiple slides may be needed to contain all sections.
Note that 2 specimens of the same age (hour) may vary in size. Larger specimens will require more cross-sectional cuts, which may require more microscope slides for mounting all sections. If more than 1 slide is needed to mount all sections, the slide label will be numbered so that the sections can be viewed in the proper sequence. The last slide in the sequence will have an “X” by this number. Because of normal size variations, chicks at 33 hours may require 2 to 6 microscope slides to mount the entire series of sections.