Natural-Historical Collections. 297 
than in structure, to which zoologists have attributed different uses. This ani- 
mal has been considered a zoophyte, and M. Cuvier thas made it the type of an 
order of that section, which he has named Free Acalepha. M. de Blainville, 
observing in its conformation a sort of symmetry, is of opinion that it ought to 
be placed higher in the scale: and, by examination, having found, like M. Sile- 
sius, at each end of the bladder a very small orifice surrounded by radiating 
fibres, he regards one as the mouth and the other as the anus; the internal sac 
furnished with ccecums, already described by M. Cuvier, appears to him to be 
the intestine ; the crest, entirely of a muscular nature, answers to the foot, which, 
in the ordinary movements of the animal, is directed upwards, like those of many 
of the swimming gasteropoda. Two little openings pierced in the right side 
anteriorly, which seem to have been observed by M. Oken, but which are not 
always found, will be the orifices of the generative organs ; in conclusion, M. de 
Blainville considers the innumerable and varied filaments, which depend from 
the body, to be branchiea. The author concludes from this arrangement of the 
external parts, that the Physalus is a mollusca, or, according to his terminology, 
a Malacozoa, and ought to be geferred to those which he names Polybranchiata, and 
Nucleobranchiata, that is to say, Tritoniacea and Pterotrachea. To confirm this 
classification, it would be necessary that the Physalus should possess a nervous 
system, a heart, a vascular system, a liver, male and female organs of generation 
with their appendages,—parts which M. Cuvier has sought for in vain. M. de 
Blainville has not yet treated of its anatomy, but he announces that he is imme- 
diately about to occupy himself therewith. 
During the same journey, M. de Blainville observed many important facts, of 
which he has given a summary to the Academy, and from which we shall only ex- 
tract some general observations, in expectation that the author will publish them 
with the necessary details. The animal of the Miliolites presents no appearance of 
tentacula, and cannot, consequently, belong to the cephalopoda, as one would 
suspect, from the examination of its shell. In the gasteropoda, which have se- 
parate sexes, the shell of the females often differs so much from that of the males, 
as to lead authors to consider them as distinct species. The eggs of many of 
these mollusca contain each a number of germs, as is also cbservable in the 
Loligo. Very often the shell in the egg is very different from that of the adult 
animal. Those organs in the Terebratule, which have been regarded as arms, 
are only branchia. The Acephala with shells, Ostracea, Camacea, &c. &c. have 
absolutely only a female sex, and each genus has a peculiar termination of the 
oviducts. The simple Ascidize have, during some time, the faculty of locomo- 
tion. The animals of the Eschara, as MM. Audouin and Milne Edwards have 
also observed, are not polypi, but approximate rather to the ascidie, &c. 
On the Primitive Vegetation of the Earth ; by Henry Witham, Esq. F.G.S. 
&c. &c.—We are indebted to Mr. Witham, for permission to make the fol- 
lowing extracts from an interesting paper on the Vegetation of the First Period 
of an Ancient World, which he lately read before the Wernerian Society, and 
which we are prevented from presenting to our readers in an entire state, from its 
being already communicated to the Annals of Philosophy by its zealous author. 
The time and attention which this gentleman has devoted to geological and 
mineralogical studies, the highly valuable museum which he has formed, and the 
general success which has attended his labours, prove how much may be effected 
by individuals, particularly when they are thrown upon their own resources by 
the inaccessible privacy of our public collections. 
Scientific men know what constant exertions Mr. Witham is making towards 
the practical elucidation of the history of primitive vegetation ; and his museum 
will always be found a deposit for illustrations of the earth’s early history, and 
his house a rendezvous for lovers of natural science. We eee wish that his 
VOL. I. P 
