194 Prof. Carl Claus on the 
starting-point of the production of the Siphonophore was 
recognized. 
Consequently the two theories no longer stood by any 
means in direct opposition, as the Polyorgan- and Polyperson- 
theories, and were also brought nearer together in that in the 
ease of the latter the derivation from the Hydroid Medusa 
might be accepted. Already it was attempted to clear up the 
mixture of truth and error, although in a different form and 
direction from Haeckel’s Medusome-theory, and, indeed, in 
favour of the Hydroid-theory, which regards the Siphono- 
phora as “swimming Hydropolyp-stocks” and deduces the 
resemblance of the larve to Meduse from cenogenetically 
altered conditions. It was necessary to modify the original 
conception formulated by R. Leuckart only so far that in the 
room of the Hydroid-stock which after separation from its 
support adopted the pelagic mode of life and acquired a hydro- 
static apparatus at its base now turned upwards, the swimming- 
larva, prevented from fixing itself but not affected in its 
nutrition, was placed, and, in agreement with the recently 
established views as to relation of the Medusa to the Polyp, 
the derivation of the Siphonophore from the Medusa as the 
sexual animal of the Hydroid-stock was recognized. 
As regards the new Classification of the Siphonophora, on 
which Haeckel has based his work, its specialities follow 
directly as consequences of his hypothesis of diphyletic 
origin. The Siphonophora are raised into a class, and 
divided into two legions or subclasses with reference to their 
binary origin:—1. The SrpHonantH#, derivable from the 
hypothetical Protomeda; and 2. The DISCONANTHA, origi- 
nating from the hypothetical Archimeda. - The first subclass 
is divided into the ordinal sections Calyconecte, Physonecte, 
and Cystonecte, which correspond to the previously recog- 
nized groups Calycophoride, Physophoride, and Physalide, 
to which are added, as a fourth order, the Auronecte, a group 
of exceedingly remarkable deep-sea forms previously unknown. 
The second subclass contains the single order Disconecte, 
which corresponds to the fourth Siphonophoran group, known 
as Chondrophoride or Discoidee. As the assumption of a 
special stem-form for the Discoidez, which may be easily and 
naturally derived from the Physophorid, seems neither 
necessary nor well founded, the alteration of the system 
founded upon it, which places the Discoidez in an equivalent 
relation to the whole of the other groups, will have to be 
rejected as a novelty by no means justified by the state of the 
case. And we eannot deal otherwise with the many new 
denominations by which Haeckel, following his previous 
