234 Miscellaneous. 
(Kolpoda, Dileptus).. Owing to the latter circumstance, it has often 
happened that the young and the adult forms of the same animal- 
cule have been described as distinct species. It is certain, for i an- 
stance, that the Glaucoma scintillans (Ehr.) is but the foetal or im- 
perfect condition of the Kolpoda cucullus (Muller). | 
In the ova of Vorticelle, having a diameter of :04 of a millimetre, 
the vitellus clearly manifests gyratory movements, in all respects re-. 
sembling those in the ova of mollusca and other animals. When the 
young Vorticella is fully developed and on the point of leaving the 
egg, this gyration is succeeded by movements of another description, 
viz. by contractions of the entire animalcule, which, as is observed, 
for example, in the young Lymnee, seems to struggle under ae 
transparent envelope of the egg. 
In the ova of Vorticelle, the animalcules of which are on the eve 
of exclusion, I have, in several instances, recognized the existence | 
of the contractile vesicle, and have noted its movements. This vesi- 
cle was proportionately of less size than in the adult animal, and its 
pulsations were less frequent. These ova, at this period entirely 
occupied by the embryo animalcule, presented a diameter of 04 milli- 
metre, and the contractile vesicle which was situated at about the 
centre, when of its greatest dimensions, ‘005 of a millimetre. : 
In the Vorticelle there exists a sac, sometimes very evident, on 
the side opposite the cardiac or contractile vesicle, and extending 
nearly the whole length of the animal. ‘Ihe interior of this sac pre- 
sents very distinct molecular movements, which seem clearly owing 
to the existence of vibratile cilia. At intervals this sac contracts 
from before backwards, and seems to transport in that direction a 
mass, distinct from the stomach vesicles which it compresses. This 
sac is the respiratory organ; and its movements have induced some 
observers to hazard the opinion of the formation of vacuoli in the 
substance of the animal, or to admit the existence of a form of 
circulation of granules, such as is noticed in vegetable cells. . 
From.what proceeds, we must regard the contractile vesicle as a 
cardiac apparatus*. It is seen to manifest itself like the punctum 
saliens of oviparous embryos. And hence we cannot with Ehrenberg 
consider it as belonging to the genital, or, with Spallanzani, to the 
respiratory apparatus. Comptes Rendus, Jan. 15th, 1849. 
[If these researches of M. Pouchet be confirmed, an important step 
in advance has been made in our knowledge of the Infusoria. We 
can no longer doubt, with M. Dujardin, the existence of ova, and of 
oviparous reproduction in the true Infusoria or Polygastrica. But 
until this confirmation be given, such exceedingly delicate observa- 
tions as those detailed must be received with some reserve; seeing 
that imagination, and the desire to indicate an analogy with the 
higher animals, are too apt to interfere with precise investigation in 
such minute beings. 
Again, respecting the contractile vesicle said to be rarweesse: _ 
* Wiegmann (Archives, 1831) surmised the cardiac nature of this con: 
tractile vesicle; and Siebold entertains the same idea:—J.T.A. 
