Johnson: Quantitative Study of Salpa chain. lti:i 



6. SALPA CYLINDKICA. 



The chain here has no curves as in 8. fusiformis-runcinata 

 and several other species, but extends straight forward along the 

 median line of the parent. This shows conclusively thai the 



Figure 13. 



bendings of the chain have nothing to do with either the double 

 rowing of the zooids or the formation of blocks. 



The chain consists of two or three blocks, and the number of 

 zooids in a block is variable. The intermediate piece and deploy- 

 ing point occur as in iS'. fusiformis-ntitciitata but the zooids of the 

 intermediate piece are less imperfect than the corresponding ones 

 of S. fusiformis-runcinata. The terminal remnant, so far as has 

 been observed, contains not more than one rudimentary zooid. 



