FORAMINIFERA AND INFUSORIA. 
345 
the appendages, were taken for testes by Ehrenberg, without any exact 
reason being given. Doyere on this remarks, very properly, that it 
must astonish us, how a contractile organ, which uninterruptedly con- 
tracts and expands itself, taking into it a fluid, and the next moment 
again rejecting it, can perform the function of a vesicula seminalis. He 
farther doubts, whether an organ like that above mentioned, covered 
with vibratile appendages, and constantly present in equal development, 
can be a vesicula seminalis and testis, for in other lower animals, the 
internal male parts of generation are only developed at certain times. 
The ring-shaped streaks, asserted by Ehrenberg to be a vascular 
system, and which are so evident in Hydatina senta, Enteroploea 
hydatina, Synchceta pectinata, Notommata collaris, and others, are 
considered by Doyere as a cuticulo-muscular system, analogous to that 
described by him as the sterno-dorsal muscle in the Tardigrade^. 
A series of very extended labours by Werneck, on Infusoria, has 
been laid before the Berlin Academy of Sciences by Ehrenberg (Bericht 
liber die Verhandl. d. Kon. Acad, der Wissensch. zu Berlin, 1841, 
p. 102 und 373). They contain a minute view of the internal structure 
of Hydatina senta, and very valuable observations on the polygastric 
animalcules, whose organs of nourishment he has not so completely 
made out as Ehrenberg has described them ; and whose contractile blad- 
ders he also asserts to be vesiculae seminales, without having recognised 
spermatozoa in them. 
The organization of the polygastric Infusoria, as described by 
Ehrenberg, has lately been questioned from many quarters. Dujardin 
(Op. cit. p. 66) has called attention to the dislocations of the so-called 
stomachs of these creatures, which could not take place if they were 
in union with each other by canals. He also has opposed the view that 
they lay eggs, possess male sexual organs, and that their coloured 
spots are organs of sight. As the nature of these spots has also been 
contended by several other observers, it is to be hoped that this conten- 
tion will call into the field, which has been opened up by the constant 
and great labour of Ehrenberg, a larger number of unprejudiced en- 
quirers, acquainted with the use of the microscope. 
Rymer Jones repeats the assertion, that he has observed in Parame- 
cium aurelia, the gastric vesicles in regular and continuous circulation ; 
nor had he, in any instance, been able to detect the central canal, or the 
branches leading from it to the vesicles. (A General Outline of the 
Animal Kingdom, and Manual of Compar. Anat. 1841, p. 59.) 
Focke saw, in Loxodes hursaria, Paramecium aurelia, and other 
polygastric Infusoria, the cavities filled with pigments, intersecting each 
other in varied series, and concluded from this, that the digestive appa- 
ratus is not separated from the parenchyma, but that the parenchyma of 
these animals, consisting of cells, encloses the fluid nourishment received 
from without in narrow spaces, which may be compared with the 
389 
