454 SUB-PHYLUM UROCHORDA OR TUNIC AT A. 



Compound Ascidians). The ventral stolon of the nurse gives rise to a 



N M 



DO 



FIG. 244. "Nurse" of Doliolum mulleri. After Uljanin. 

 I., Inhalant, E., exhalant aperture ; C. ciliated band round 



number of primitive buds, which migrate over the body until they reach 

 a dorsal outgrowth, apparently well supplied with blood. Here they 



FlG. 245. Sexual individual of Doliolum mulleri. 

 ^ After Uljanin. 



G., gonads ; B., gill-slits ; other letters as before. The unlettered 

 reference line points to the stomach. 



fix themselves and divide up to form three series of buds two lateral 

 and one median. All these buds develop into individuals belonging to 



