LIMNOCNIDA TANGANICiE. 
101 
“Wahrend sie (die Glocke) im Beginn der Phylogenese 
der Medusen auch in der Ontogenese als Kreisrunder Kelch 
im Umkreis der Basis des Manubriums mifc freiem Rande 
emporwuchs, fand nun derselbe Prozess gewissermassen in 
umgekehrtem Sinn statt, indem die Kuppe der Knospe den 
Glockenrand dadurch bildete, dass sich das Ectoderm hier 
nach iunen einstiilpte. 
“Bei weiterer Yerkiirzung der Ontogenese wurde diese 
Einstiilpung zu einer blossen soliden Einwucherung ohne 
Einstiilpungspforte und damit sind wir beim heutigen 
Glockenrand angelangt, der seine Abstammung von einer 
Einstiilpung des Ectoderms auch heute in einzelnen Fallen 
noch erkennen lasst.” 
According to Weismann's views sessile gonophores are 
merely degenerate medusae. 
Goette's studies on the development of the gonophores of 
a large number of Hydroids have led him to very different 
and somewhat startling conclusions. He considers that 
medusoid and hydroid individuals are not truly homologous, 
and takes a quite opposite view to Weismann, believing that 
the medusae have not arisen from any kind of polyp-form, but 
represent completely new structures formed as the culminating 
points of long series of sessile gonophores of increasing com- 
plexity. 
In a short preliminary paper, published in the ‘ Zoologischer 
Anzeiger' (12), Hadzi subjects Goette’s theoretical conclusions 
to a severe criticism, and (in my opinion) very justly con- 
demns them as erroneous ; he very clearly demonstrates that 
the medusa-form in the Hydromedusm can be derived directly 
from the polyp-form, even in the light of the recent investiga- 
tions of the development of gonophores. 
Hadzi revives and modifies an old theory of Allman's (15), 
and would derive the medusoid individual from some such 
polyp as that of Laomedea or Cam panop sis, in which the 
tentacle bases are joined together by a web-like, solid duplica- 
ture of ectoderm. He points out that if we consider the 
umbrella to have arisen from such a double fold of ectoderm 
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