SALPA DEVELOPMENT OF THE BUDS ON THE STOLON. 507 



are hollow, and each of them contains a blood-vessel. These might 

 be compared to the mantle-vessels of the Ascidians. The final 

 connection between the individuals is formed by the processes of 

 neighbouring individuals growing out towards one another and 

 fusing. Each of 'the individuals belonging to a chain possesses, as 

 a rule, eight of these processes placed in four longitudinal rows ; 

 two ventral and two lateral. The lateral couplings serve for attach- 

 ment to the individuals lying in the same longitudinal row, while the 

 ventral processes establish a connection between the two parallel rows 



FIG. 276. Diagram illustrating the relations of the connecting strand (st) to the buds 

 on the stolon of a Salpa. A, represents the stolon from Fig. 268 viewed from above ; 

 B, shows the condition after rotation has taken place ; G, the condition after the 

 buds have sunk downward, a, distal end of the connecting strand, b, proximal end 

 of the same ; d, distal part of stolon ; es, endostyle-folds ; h, haemal or ventral side ; 

 n, nervous system and neural or dorsal side ; p, proximal part of stolon ; st, connect- 

 ing strands. 



of individuals seen in the diagram (Fig. 277 A). The long axes of 

 the individuals are inclined somewhat obliquely to that of the chain, 

 a position which results from the fact that the couplings are not 

 inserted at the same level on the right and the left sides of the body 

 (Fig. 277 B). This oblique position may have given rise to the 

 horizontal one seen in Salpa fusiformis. In S. (Cyclosalpd) pinnata 

 the individuals are found arranged in the form of a rosette, each of 

 the buds giving off a single process only from the ventral side which 

 runs towards the centre of the rosette, where all the processes meet 



