FORAMINIFERA AND INFUSORIA. 
343 
He has also examined the intimate structure of the Corallince, (Edin. New 
Phil. Journ. vol. xxiii. 1842, p. 206, or Fror. Neue Notiz. Bd. 23, p. 154). 
After removing the calcareous portions by means of nitric acid, he saw 
a tissue of net-work, and sometimes also siliceous spicula remaining ; and 
between the tissue gemmular bodies, which, in his opinion, must have 
been polype germs. 
A new classification of the sponges has been proposed by Hogg (Ann. 
Nat. Hist. viii. p. 3), in which he divides them into five sections, accord- 
ing to the construction of their parenchyma: 1. Spongice subcornew, 
parenchyma without spicula ; 2. Spongice subcorneo-silicece, parenchyma 
with numerous siliceous spicula ; 3. Spongice subcartilagineo-calcarice, 
parenchyma with calcareous spicula ; 4. Spongice subcartilagineo-silicece ; 
and 5. Spongice subereo-silicece. 
A new horny sponge has been described by Owen, under the name of 
Enplectella aspergillum (ibid. p. 222), which is cylindrical, hollow like 
a cornucopia, and composed of a regular net- work. The material of this 
resembles dried gluten, and burns away to a charry residuum. 
FORAMINIFERA AND INFUSORIA. 
Ehrenberg continues his researches into the microscopic organisms of 
the past and present world, and gives by them an always firmer and 
broader basis to the surprising conclusion he had come to, that these 
microscopic beings exercise the greatest influence on the solid surface of 
our earth. 
He has convinced himself, that the calcareous rocks of Syria and of 
central North America, contain densely-crowded masses of small Poly- 
thalamice (Bericht fiber die zur Bekanntmachung geeigneten Verhandl. 
der Konigl. Akad. der Wissenschaften zu Berlin, 1842, p. 187), several 
species of which, from the North American limestone, completely agree 
with the Polythalamice of the European chalk. 
Ehrenberg also found the plastic marl of ^gina to consist of small 
organisms, several species of which belong to the chalk animalcules 
(ibid. p. 263). He mentions, moreover, that the limestone hills of Lake 
Onega, in Russia, consist partly of small Polythalamice (ibid. p. 273). 
He has also taken some pains to investigate the structure of these won- 
derful chalk animalcules (Abhandl. d. Kon. Akad. d. Wissensch. in Ber- 
lin, 1841, p. 106). He recognised no external, but only an internal 
body covering the shell of these animals, which allowed very long, fine, 
expansible, palpal threads, to pass out from all parts of the cribriform 
shell. He does not confirm the account of D’Orbigny, that all these 
animalcules possess a protrusible head, covered by a plumular palpal 
apparatus. According to the researches of Dujardin, the animal of the 
387 
