These vertebrae are developed round an unsegmented rod, the notochord, which forms the axial support of the embryo.
Any one of them might be the unsegmented gut of the segmented animal.
The notochordal tube is unsegmented, although the vertebrate is markedly segmented.
Pro' leg, an unsegmented appendage found in the larv of some insects.
The somites are first formed in the neck, and are added successively behind in the unsegmented posterior region of the embryo.
I did not succeed in determining whether, as in Dentalium, this early localization in Lanice pre-exists in the unsegmented egg.
The shaft was apparently rather short, unsegmented, and fairly broad.
The notochord in living forms is unsegmented, but segmented cartilaginous neural arches are present in some cases.
The thorax is unsegmented and indeed almost unrepresented, but the abdomen is long and divided into distinct segments.
The body in most cases is unsegmented, and bears anteriorly a single median eye.
1560s, from Latin segmentum "a strip or piece cut off, a cutting, strips of colored cloth," from secare "to cut" (see section (n.)), with euphonious alteration of -c- to -g- before -m-. Latin segmentum was used in Medieval Latin as a geometry term, translating Greek tmema, and the word was first picked up in English in this sense. Meaning "segmental portion of anything circular" is from 1640s; general sense of "a division, section" is from 1762.
1859, intransitive, in reference to cell division, from segment (n.). Transitive sense, "divide (something) into segments" is from 1872. Related: Segmented; segmenting.
segment seg·ment (sěg'mənt)
A clearly differentiated subdivision of an organism or part, such as a metamere.
A part of an organ having independent function, supply, or drainage.