SOME OBSERVATIONS ON ACINETARIA. 633 
synonomous with MHinck’s Ophryodendron  pedicel- 
latum). von Koch describes the proboscidiform and vermi- 
form individuals which he terms respectively forms A and B. 
He does not describe the ciliated embryos, but he puts for- 
ward the novel view that the cases of association between the 
individuals A and B which Claparéde and Lachmann and 
Hincks considered as probable cases of budding, were rather 
to be regarded in the inverse order, as the gradual stages of 
a complete copulation between the individual A and B, which 
would probably result in the formation of internal buds, as 
may be seen from the following passage: “ Aus den Embry- 
onen entwickeln sich die zwei verschieden gestalteten Formen 
A and B. B (the vermiform individual) lost sich nach eine 
gewisse Zeit von seinem Stiel ab, und es verschmilzt Pro- 
toplasma und Kern mit denselben l'heilen von A (the pro- 
boscidiform individual). Nach dieser Verschmelzung werden 
von A und B endogene Hmbryonen erzeugt. Gegen diese 
Deutung lasst sich aus meinen Beobachtungen keine Kinwen- 
dung machen.” 
Koch’s principal reason for this interpretation seems to 
have been the fact that he could not recognise any trace of 
the stalk in the full-grown vermiform individuals which he 
saw in contact with the proboscidiform. 
The reason for this, as will be shown later, is that the stalk 
is usually only formed after the vermiform individual has 
become free from the proboscidiform parent. 
Fraipont, in 1877, returned to the original view of Claparéde 
and Lachmann, that the vermiform individuals are a stage in 
the development of the proboscidiform individuals, though he 
describes the vermiform individuals as characterised “ par 
absence de trompe proprement dite, et de sucoirs prehen- 
seurs” (p. 783). It is very difficult to form a clear concep- 
tion as to his views on external budding. On p. 791 he 
states that, “Les Proboscidiens donnent naissance par 
bourgeonnement externe a des individus semblables 4 eux 
soit directement soit aprés quwils ont passé par la phase 
d@individus Lageéniformes.” Whereas on p. 789 the following 
