62 BULLETIN OF THE 
the ganglion gradually assuming the position it has in the adult, on the 
anal side of the pharynx at the base of the anal tentacles. 
A section across the pharynx in such a stage as Figure 83 is shown 
in Figure 87. A comparison with Figure ‘51 (Plate V.) of my Crista- 
tella paper (Davenport, ’90) will show a great similarity of conditions at 
about the same age, and can leave no doubt concerning the homology of 
the regions marked in both cases lu. gm. ; or compare Taf. VIII. Fig. 100, 
nh., of Braem’s (90) magnificent work. A section through a later stage 
is shown in Figure 82. The brain has already sent out circumoesopha- 
geal nerves, as in Paludicella. The central part of the ganglion does 
not stain; one sees only a granular mass, sometimes with signs of short 
fibres. In the cornua (n’) one occasionally sees very large clear nuclei 
with a single nucleolus, lying in the midst of a cell mass which is 
spindle-shaped and stains more deeply than adjacent cells. These remind 
one strongly of bipolar ganglionic cells, but fibres could not be traced 
far from their pointed ends. Series of sections of Flustrella parallel to 
Figure 82 show, as one passes below the level of the ganglion, a con- 
tinuous band of cells extending down from it towards the cardiac valve 
and between the cell layer lining the esophagus and the surrounding 
mesoderm. One is reminded of the exactly similar conditions in Palu- 
dicella (page 26), and of the “linienartige Zeichnung” seen by Nitsche 
(71, p. 431) and Vigelius (84, p. 42) in the same place in Flustra. 
These facts go to indicate the existence of a gastric nerve. 
At about the time at which the ganglion arises, the cavities of the 
stomach and the wsophagus become confluent (Fig. 86 @.). At this 
stage (somewhat earlier than Figure 86) the alimentary tract consists 
of a U-shaped tube of nearly uniform calibre, and without any indica- 
tion of the cecum. The tentacles lie in two parallel rows in the middle 
of the bud, the corona being incomplete both in front and behind, but 
less so oralwards than towards the anus (Fig. 77, atr.). In fact, while 
new tentacles are formed later towards the oral median line, they never 
appear behind the line atr. This hinder region has another fate. Its 
wall increases very greatly in area, diminishes correspondingly in thick- 
ness, and forms a large part of the kamptoderm lying behind the post- 
oral tentacle in Figure 86. With this growth of the kamptoderm the 
anus is carried backwards, and farther and farther from the posterior 
ends of the rows of tentacles, immediately behind which it formerly lay. 
As the kamptoderm grows in area, the polypide comes to lie in the 
proximal part of the zowcium, Pari passu with this process occurs the 
rotation of the oral tentacles, as in Paludicella. The oral tentacles which 
