164 RITTER. [ViGL.X ie 
One of two conclusions seems to be inevitable from the facts 
observed: Ezther there are no budding zones containing specially 
endowed cells; or a large majority of zootds are incapable of 
producing buds. 
It is true that a comparatively small number of zooids with 
buds actually in connection with them have been found; but I 
suppose this to be due generally to the early stage at which 
the buds are severed from their parents, rather than to the 
incapacity of the zooids to produce buds. But I would by no 
means assert that all zooids are capable of asexual reproduc- 
tion. Later stages in the development of buds, though before 
severance from their parents, are shown in Figs. gand 10, Pl. XII. 
and Figs. 12-15, Pl. XIII. Fig. 9, Pl. XII, represents a zooid 
with its bud, seen as a transparent object, but not sufficiently 
cleared to render distinctly visible the several organs and 
layers. On the other hand, Fig. 10 was drawn from a speci- 
men well cleared in cedar oil, and consequently so transparent 
as to make the optical section at the level represented almost 
as distinct in its various parts as an actual section in the same 
plane would be. These figures explain themselves sufficiently. 
The position of the buds far forward on the zooids will be 
noticed in all these cases. This appears to be their usual 
position. A transverse section of a bud of a stage about 
corresponding to that shown in Fig. 10 is presented in Fig. 
14. This represents the tenth section from the tip of the 
bud. The thickness and irregularity of the inner vesicle are 
here conspicuous. The sections of the same series near the 
parent zooid show the inner vesicle to be here considerably 
thinner than it is in the section figured. The difference in 
thickness in the two regions is, I suppose, due to the fact that 
growth is taking place chiefly toward the end of the bud. The 
thinner, basal part is where, a little later, the endoderm will 
become disorganized in course of the cutting off of the bud 
from the parent. 
The question may arise here if the unequal thickness of the 
endoderm at various points, as shown in Fig. 10, is not an 
indication that the differentiation of the organs has begun at 
this stage. 
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