EXPERIMENTAL OBSERVATIONS ON PENNATULTDS. 455 
A short time after the two basal apertures became 
apparent, minute streams of methylene blue were observed 
to emerge from six additional apertures, also about the base 
of the stalk, four of which were definitely arranged to form 
the four corners of a square wlien viewed basally (fig. 2) and 
the other two laterally placed but in close proximity to the 
dorsal and ventral apertures. Particles of carmine were 
observed in a state of extrusion from one only of all the six 
apertures (fig. 2, L.Ap.). 
Particles of carmine were also observed in a state of extru- 
sion from the mouths of the autozooids and of the siphono- 
zooids (fig. 7), but only extremely minute particles were seen 
to be expelled from the latter ; it may have been impossible 
for lai’ger particles to escape that way. 
'Idle specimen under consideration differed from all othei’s 
which I have had the opportunity of examining in the presence 
of an aggregation of unusually larg-e siphonozooids in the 
region superior to that occupied by the dorsal pores (fig. 5, 
From these zooids I observed no instance during the experi- 
ment of the extrusion of carmine or methylene blue. It is 
possible that at the time of examination the injecting fluids 
had not then penetrated to that particular region; but it was 
very evident that currents were passing outwards from these 
siphonozooids, for clouds of methylene blue squirted among 
them were immediately dispersed in an outward direction. 
On the third day the colony was fixed and preserved for 
future examination in a moderately hot 7 per cent, aqueous 
solution of formalin. 
At intervals during the month of April this experiment was 
repeated on other freshly captured specimens of Pennatula 
rubra, and in three instances in specimens of the species 
P. phosphorea. 
The results in all cases were very similar in character. 
Four dorsal poi’es in the act of extrusion of coloured liquids 
and solid carmine particles were observed in all the specimens 
examined of both species (fig. 5, D.P.) 
The large basal apertures of the dorsal and ventral canals 
