III SALZPA——-REPRODUCTION 103 
another, the aggregated form being usually more rounded, ovoid, 
or fusiform (Fig. 61, A), and the solitary more quadrangular, 
and often provided with conical processes.or projecting points. 
The solitary form gives rise, by gemmation at the posterior 
end of the endostyle (Fig. 63), to a complex tubular stolon, con- 
Fic. 63.—Diagram to 
show the relations 
of the groups of 
young buds, when 
first formed on the 
stolon of Salpa. at, 
Atrial aperture ; b7, 
branchial aperture ; 
el, elaeoblast ; end, 
endostyle ; , heart ; 
N.g, nerve - gang- 
lion ; ov, ovum ; s, stolon ; st, stomach ; I, II, III, groups of buds. (After Brooks.) 
taining processes from the more important organs of the parent- 
body, which give rise to an endodermal tube, two peribranchial 
tubes, a neural tube, two blood-sinuses and mesoblast cells, a 
genital cord, and over all the ectodermal covering (see Fig. 64). 
This stolon becomes segmented (Fig. 63) into a series of buds or 
Fic. 64.—Transverse 
section through 
endostyle and 
young stolon of 
Salpa pinnata, ec, 
Ectoderm of parent 
reflected at ec’ to 
cover base of 
stolon ; ec’’, ecto- 
derm of  stolon ; 
end, endoderm of 
stolon; g, ovary ; 
mes, mesoderm 
cells; nm, nerve- 
tube of stolon; 
p.br, peribranchial 
tubes of stolon. 
(After Brooks.) 
young “chain” individuals, of which there may be several 
hundreds. As the stolon elongates (Fig. 61, B, st”), the buds 
