28 BULLETIN OF THE 
6. Formation of the Indivdual. 
Recent careful studies on the formation of the individual in other 
Endoprocta, especially by Seeliger (’89*), render a detailed study of this 
process less necessary. There are a few points concerning the physio- 
logical rather more than the morphological features of this process which 
I have attended to in this case in order to test certain conclusions which 
I had arrived at from the study of the earliest stages of budding in 
Ectoprocta. 
First, the budding regions are areas of cuboidal cells, with relatively 
large nuclei and deeply staining plasma. Such a condition is found in 
both the ectoderm and mesoderm of the proliferating region (Plate VI. 
Figs. 50, 57). The relative enlargement of the ectodermal cells, and 
at the same time a bending of the whole layer outward, give rise to 
the first fundament of the new individual. The musculature of the 
new individuals is certainly not derived directly from that of the old 
stalk, for this takes no part in the outbending. Upon the apex of the 
cylindrical protuberance thus formed the polypide is produced. The 
details of this process I have not followed. 
Secondly, the position and time of origin of the buds arising from the 
stalk are very definite. They make their appearance in a zone lying in 
the lower part of the segment (Plate VI. Figs. 50, 58-60), and shortly 
after the formation of the dissepiment which lies just below. 
One of the questions the re-examination of which most interested 
me was that of the origin of the alimentary tract, since this is stated to 
arise differently in Endoprocta and Ectoprocta. 
In an optical section of the whole bud (Plate VI. Fig. 53), it could 
be seen that the atrium was connected with the young alimentary tract 
at the oral end only. The same thing is shown in the series of trans- 
verse sections, Figures 54-56, in which the distal (anal) part of the 
atrial chamber is not confluent with the rudiment of the alimentary 
tract which touches its floor, Figure 54, but the two organs are con- 
fluent at the proximal (oral) part, Figure 56. Figure 52 is from an 
optical longitudinal section of the bud shown in Figure 53, taken in a 
plane perpendicular to that of Figure 53. Here the alimentary tract, st. 
(Fig. 52; ga. Fig. 53) is being constricted off from the atrium. 
Like the young bud, the growing tip of the stolon possesses an ecto- 
derm consisting of large cuboidal cells (Plate VI. Fig. 57). The mesen- 
chymatous tissue also consists of thickly crowded, undifferentiated, and 
deeply staining cells (Figures 51, 57). 
