1876.) A Remarkable Life History and its Meaning. 653 
a chain-salpa, containing an embryo of the solitary form, s, which 
is also ready to be discharged. It will at once be seen, by a com- 
parison of these figures, that although the two forms differ little 
in size when full grown, the solitary form is many hundred times 
larger than the chain-salpa at birth. After the embryo escapes 
from the body of the chain-salpa, the testicle of the latter be- 
comes fully developed, and its spermatic fluid is discharged into 
the water to gain access to the breathing chambers of younger 
l the animals of the chains, while these are produced asexually as 
able to 
