β Scribed by T. M. Spight; A. Lyons
No coin nor oath required. For personal study only.
The shell of the adult Ceratostvma /oliatum (Gmelin) is characterized by three variees with foliations, and a tooth on the anterior portion of the outer lip. These features are derived gradually from the markedly different sculp~m3 of shells of small juveniles (a network of fine axial and spiral cords). The sculpture changes as the thin, cord-like basic varix is elaboraf~d, reinforced, and modified by the development of a secondary structure (the tooth) and a~ the number of variees per whorl decreases. Most muricid shell patterns can be derived from juvenile patterns similar to that of C./olioAum by quantitative variations in these four processes. Likely functions of the complex and varied muricid shell strucVures inelude stabilization in shift~ substrates, defense again~ predatom, and strengthening of the shell. ~Different functions and shell-grow~ pat-~erns are likely for the different types ofvarices. Shell structur~ are most elaborate on shells of adults. A s~ucture's functions are likely to change as the Structure becomes more complex on each successive whorl. The functional ~mriod in an individual's lffe~)an is consequently restricted by the pattern of growth, the rate of structural development, and the rate of shell erosion.
π SIMILAR VOLUMES
## Abstract The vertebrate spleen has important functions in immunity and haematopoiesis, many of which have been well studied. In contrast, we know much less about the mechanisms governing its early embryonic development. However, as a result of work over the past decadeβmostly using knockout mice