Organism of the Siphonophora. 195 
custom, without any sufficient reason, wishes to make a 
number of old names which have obtained a footing in science 
disappear. Not only are new designations given to the orders 
and to many families and genera, but a new nomenclature is 
introduced, quite unnecessarily, for the parts and appendages 
of the Siphonophora. 
In accordance with the fiction of the Medusome-notion all 
organs which may have originally belonged to a Medusa- 
person are comprised as a ‘‘ Medusome,” and palingenetic are 
distinguished from ceenogenetic Medusomes. In the former 
the chief organs are considered to have remained more or less 
in their original connexion, while in the latter they have been 
more or less dislocated in consequence of cenogenetic dis- 
placement, and a secondary increase of homologous parts, a 
“‘ multiplication ” of the organs, has taken place. Groups of 
correlated Medusomes are denominated cormidia, and these 
are distinguished as ordinate (Cormidia ordinata) when they 
are repeated in metameric sequence, and dissolved ( Cormidia 
dissoluta) when they are scattered on the stem and their 
organs are separated from each other. The swimming column 
is henceforth to be called the ‘‘ Nectosome,” the stem fol- 
lowing beneath this the ‘‘ Siphosome,” the swimming-bell the 
“‘Nectophore;”’ the gastric sac or nutritive polyp is re- 
christened “Siphon,” and the feelers (taster) ‘‘ Palpons ;” 
the filaments (Hangfaden) are called “ Tentacles” *, the ter- 
minal threads on the urticating nodes “ Tentilla,” the sub- 
sidiary filaments of the taster ‘‘ Palpacles,” the tentaculiform 
appendage with a terminal aperture ‘‘ Cyston,” the covering 
pieces ‘‘ Bracts,” the taster or gastral tube bearing sexual 
buds “‘ Gonostyle,” and the sexual buds themselves “ Gono- 
phores.” In the air-chamber or pneumatophore we find the 
air-sac denominated the ‘‘ Pneumatosaccus,”’ the air-flask the 
“‘ Pneumatocystis,” its lower part which functions as a gas- 
gland the ‘‘ Pneumadenia,” and the basal aperture or funnel 
of this the “ Pneumatopyle.” That Haeckel makes a very 
* In my writings I have repeatedly made use of the expression “ ten- 
tacles”’ as synonymous with “ tasters,” just as the “ feelers” of the Mol- 
lusea are usually called “tentacles.” With Haeckel, who designates the 
“stinging filaments” as tentacles, this different use of the word leads to 
the following logical conclusion :—“ Not unfrequently palpons are con- 
fused with tentacles, as, for instance, repeatedly by Claus, even in Physo- 
phora” (‘ Report, pp. 17, 193, 260). A glance at my memoirs, and 
especially that on Halistemma (1878), will at once convince any one that 
I use “ tentacle” as synonymous with “ taster,” and adopt the two deno- 
minations indifferently, so that there can be no question of a confusion 
with ‘‘ stinging filaments.” Moreover it is quite incomprehensible how 
any one could confound the “tasters” with the “ stinging filaments,” 
especially in Physophora, 
