Characteristics of the crushing stage (for example, lancelet).

Fragmentation is the second stage of ontogenesis (individual development of the organism). The feature of crushing is a special form of division, the essence of which is as follows:
Daughter cells, after division, do not diverge from each other. Thus, they contribute to the formation of a multicellular embryo;
With repeated division, daughter cells, otherwise blastomeres, decrease in size;
The first two divisions (at the lancelet) proceed in the longitudinal direction. The next division goes in the transverse direction. And then the longitudinal and transverse divisions alternate.