Breaks caused by chromosome aberrations in regions with repeats may not result in a sharp decline of viability, so that break points of chromosome rearrangements in intercalary heterochromatin may be more frequent than in other regions.
Source: wiktionary
In this new model, the anterior and posterior blastemas were formed as signaling centers to direct intercalary reorganization of body regionality or positional information.
Source: wiktionary
...two radial cells, second longer than first; intercalary fork fairly distinct; crossvein r-m vertical...
Source: wiktionary