Immunohistological studies on the distribution of yolk proteins in the stick insect (Carausius morosus)

The path of yolk proteins through stick insect embryos at two developmental levels was studied immunologically. In 18-day-old embryos, all the blastema takes up the yolk proteins directly. In 30-day-old embryos, two transport systems are developed: embryonic contraction moves the yolk particles throughout the embryonic cavities, and amoeboid cells complete the yolk transport to its destination.