414 E . R. Downie, 
Relation of the bud to the spermary. 
Lane (57) gives the initiation of the budding process in Hydra 
as follows: The beginning of the bud is marked by the karyo- 
kinetic division of the interstitial cells which thus increase until 
the ectoderm is double its normal thickness. Then the mesogloea 
disappears and cells wander from the ectoderm into the endoderm 
until the former is reduced to its normal thickness. The meso- 
gloea now reforms and in the thickened endoderm the new body 
cavity appears. The point particulary to be noted is that it is 
the increase of interstitial cells by karyokinesis and their accumu- 
lation in the ectoderm that gives rise to the early stages of the 
bud. The similarity of this process to the initiation of the spermary 
is apparent, and lends support to the attempts made before to homo- 
logize buds and spermaries. Since both processes are dependent on 
the interstitial cells, it is evident that the budding zone and the 
zone of reproductive organs must coincide. It is to be recalled that 
in Hydra, so far as observed, when sexual organs appear on a 
budding individual they appear on the bud and not on the parent 
stock. If this expresses the rule, sexual organs appearing on the 
vigorous bud rather than on the parent partially exhausted by 
budding, then we need only conceive of the process carried to the 
point where the bud always produces the sexual organs, and at an 
increasingly early stage, to see how from a primitive form like 
Hydra, a complex colonial form might be established, with buds 
specialized as gonophores. This does not imply that Hydra is necess- 
arily the primitive form. It may be a degenerate. The homology 
in the early stages of budding and formation of the spermary would 
seem to permit of such an interpretation. The spermary would 
represent a degenerate bud. The line of degeneration would pass 
from a hydroid with free swimming sexually mature medusae like 
Pennaria, though hydroids with attached medusae (Tubularia) with 
attached gonophores evidently medusa buds (Clava) with attached 
gonophores that are evidently degenerate medusae (Campanularia), 
with gonophores that are scarcely recognized medusae (Cordylophora) 
to Hydra in which the gonophore can only be recognized as a bud 
in the very earliest stage. Since the process of budding departs 
from that of spermary formation at so early a stage and seems to 
occur under such different physiological conditions, and since Hydra 
has no other marks of degeneration either in its embryolgy or 
