104 



EMBRTOLOGY 



(ScypMstoma) appears to lack the power of generating sexual 

 products, exhibiting only non-sexual reproduction, which 

 occurs in two modifications : (1) as budding (lateral budding 

 and formation of root-runners or stolons) (Fig. 50), by means 

 of which a scyphopolyp is always produced again — this 

 either separates from the parent and attaches itself independ- 

 ently, or may remain united with the parent, thus tem- 

 porarily producing small colonies (scyphopolyp stocks) — (2) 



Fig. 51. — Cycle of development of Aurelia aiirifa (from Hatschek's Lehrbuch). 

 ], planula ; 2, attached larva; 3, young Scyphistoma with four tentacular buds; 4, 

 Scyphistoma with stolonic growth ; 5, beginning of the^strobilization, indicated by 

 a circular furrow ; 6, 8, 9, 10, various strobite polydiscse ; 7, Scyphistoma from 

 above ; 11, Ephyra from the side ; 12, Ephyra from below. 



as strobilization, in reality a transverse division with subse- 

 quent regeneration. By means of transverse constrictions 

 the scyphopolyp (Fig. 51, e) separates into superposed dis- 

 coid parts (sfrobila stage, Fig. 51, 5 — 10), each one of which, 

 by the production of marginal lobes and corresponding 

 internal metamorphoses, is changed into a young medusa, 

 which at first shows the characteristic form of the Ephyra 

 stage (Fig. 51, n, 12), and is not converted into the permanent 



