SUB-PHYLUM UROCHORDA OR TUNICATA. 
454 
Compound Ascidians). The ventral stolon of the nurse gives rise to a 
P QO : M Do 
I i { _FTE cl 
c =| 10). : Nf 4 -E 
=F a 
En F 
Hoe D 
Fic. 244.—‘‘ Nurse” of Doliolum miiller?.—After Uljanin. 
I, Inhalant, E., exhalant aperture; C., ciliated band round 
peas (P.); En., endastyle ; O., ‘‘ otocyst” ; N., nerve-gang- 
ion; H., heart ; C&., cesophageal opening; D., stomach; A., 
anus; Cl., cloaca; DO., dorsal organ; M., muscle bands. 
number of primitive buds, which migrate over the body until they reach 
a dorsal outgrowth, apparently well supplied with blood. Here they 
N M 
P B 
— 
OE 
En H G 
Fic. 245.—Sexual individual of Doliolum miller. — 
After Uljanin. 
G., gonads ; B., gill-slits ; other letters as before. 
reference line points to the stomach. 
The unlettered 
fix themselves and divide up to form three series of buds—two lateral 
and one median. All these buds develop into individuals belonging to 
