SCIENTIFIC SUMMARY. 
143 
has always been received with a great dep,l of doubt, but now Mr. J. Swain, of 
Philadelphia, has come forward to corroborate (unintentionally) the assertion 
of Huber. Beheving that he is the first who has observed these peculiar 
habitations, he has transmitted specimens of them found on the branches of 
Vernonia novehoracensis to the French Academy. MM. Edwards and 
Blanchard, to whom they were committed for examination, admit the correct- 
ness of Mr. Swain’s observations, but assign to him only the merit of having 
discovered that the American ants have similar tastes for luxury to those of 
their European relatives. — Vide Comptes Mencius, Aug. 1. 
The Geographical Distribution of Annelids. — M. Be Quatrefages has just 
completed his great treatise on the Annelid group and its distribution, and 
has drawn the following conclusions as to the manner in which the members 
of this class are spread over the globe : — (1) The class of Annelids properly 
so called {Errantes and Tubicola), has the same area in salt water as the earth- 
worm and nais have in fresh water. (2) The former division (to which alone 
M. De Quatrefages applies the term Annelids), has representatives in every 
sea. (3) This wide range seems to extend to the more typical genera of this 
class, as well as to the most exceptional sub-types. (4) Hence the Annelid 
fauna presents no division into zoologic regions or centres of creation, which 
in other classes are so well marked out. (5) The tendency to the diffusion 
of genera and sub-genera is counterbalanced by the tendency to the localisa- 
tion of species. (6) The number of similar species inhabiting the two con- 
tinents, if not represented by cypher, must always be extremely limited. There 
is but one species common to the French and Mediterranean shores. (7) 
The few exceptions to the law of localization of species may be explained by 
reference to the action of marine currents. Thus it was that I found Eous- 
seau’s large Eunice at Saint- Jean-de-Luz, a species which Cuvier confounded 
with the great Eunice of the Indian seas. This worm, which belongs to the 
Antilles, had evidently been carried by the current of the gulf-stream from 
the coast of Mexico. (8) From the wide area of distribution possessed by 
the types, and the locahsation of the species, it foUows that we must not look 
for corresponding geographical limits in the latter. (9) The Annelid class 
does not present elevation or degradation of organisation in accordance with 
latitude, a phenomenon which is exceedingly well marked in other groups, as 
the Crustacea, for example. Equality of organisation is one of the most con- 
stant laws regulating this group of beings. (10) The nature of the coast line 
influences the development of the Annelid fauna to a great extent : thus on 
granite and schistose shores, the number of species and individuals is large, 
whilst on calcareous coasts it is correspondingly small. 
Phenomena observed during the Death of Sponges. — Herr Lieberkiihn has 
found that during the decay, or rather death of the sponge, it sends out a series 
of peculiar prolongations which travel over the siliceous skeleton, and at length 
find their way to the bottom of the vessel and develope spicules and cilia. 
He also states that dying sponges frequently divide into particles whose 
structure and characters *are not to be distinguished from those of the parent. 
Whether these be original discoveries or not remains to be shown, but it 
seems to us that the process described by Herr Lieberhulin is very similar to 
the ordinary mode of development of spongilla, which has been so carefully 
studied by Carter and others. 
