MY HI APOD A 



391 



development these three parts of each of the coelomic sacs are not dis- 

 tinctly separated from each other, the visceral wall of each forming a 

 common cover for all of them. Some cells of this visceral wall become free 

 later to attach themselves to the entoderm epithelium (Fig. 348, ent) 



W 



coel I 



Fig. 348. — Scolopendra cingulata. Cross section, left half, {chl) Cardioblasts. {coel) 

 Coelome. {ent) Entoderm cell. (/) Fat body. {g. coel) Genital coelome. {mus) Muscle. 

 {mst) Middle strand, {nc) Nerve cord, {splm) Splanchnic mesoderm, {st) Stigmata. 

 (ster) Sternite. (2/c) Yolk cell. {Adapted from Heymons.) 



where they multiply and form a thin cellular layer, the anlage of the 

 mid-gut muscle layer (Fig. 348, splm). Dorsal and ventral longitudinal 

 muscles arise by proliferation of cells from the somatic wall of the coelomic 

 sacs of the rump segments, the dorsal above, the ventral below the rudi- 

 ments of the appendages (Fig. 348, mus). In a similar manner the 

 mesoderm which lines the appendages is the scene of proliferations and 



