STILL FOUND IN A LIVING STATE, 325 
_ powerful defenders, and has maintained its ground to the present 
day. 
As the first traces of fossil Infusoria were recognised only four 
"years ago, it was not surprising that their forms appeared for 
the greatest part perfectly identical with existing ones ; and it 
was obviously more essential to make further careful search 
among the living, than to regard such as were not identical with 
those now existing as actually extinct; for the relations under 
_which they presented themselves to observation belonged to the 
outermost surface of the earth’s crust. The phenomenon at 
Bilin now excited curiosity and almost surprise, namely, that 
- the polishing slate* of that place, situated according to Elie de 
_ Beaumont’s opinion + above the upper greensand f, and to be as- 
_ signed to the middle division of the geological tertiary period, 
_ together with its semi-opals, was found to consist of more than 
two-thirds of now living species; nay, the very animal (Gallionella 
listans) principaliy constituting the mass, was found alive near 
Berlin. So likewise (to say nothing of the superficially oc- 
eurring farinaceous loose Bergmehls and Kieselguhrs) there were 
also found four-fifths of existing specigs of Infusoria in the 
"polishing slate from Habichtswald near Cassel which distinctly 
belongs to the tertiary formation. It seemed to result from 
hence, that the infusorial forms had continued to exist from the 
i § * Polirschiefer.—See Prof. Ehrenberg on Fossil Infusoria, Art. XX. of our 
_ First Volume, p. 400.—Eb. 
_ + Comptes Rendus, 1838, ii. p. 501. It seems necessary to observe here, that 
the meritorious geologist is evidently @ priori rather inclined to ascribe this 
deposit to the more superficial relations, but nevertheless assigns it decidedly 
enough to the middle tertiary period. M. Turpin’s analysis of the specimens 
furnished him by E. de Beaumont is most strangely and surprisingly mangué. 
He powdered the mass of the semi-opal to test it microscopically, by which 
process all organisms were of course rendered indistinct and destroyed, and 
then states that he found in them few organic constituents; but, neverthe- 
less, there were still ameng the constituents found a Protococeus (!), and other 
_ blackish globules, which he regards as Infusoria eggs (!), and in part as mere 
age of the egg-shells (!!). He further found organic filaments, and an insect’s 
eg (!), all of which he has figured. It seems to me as if M. Turpin had dis- 
cerned nothing of the organized beings of the Bilin stone, but rather given a 
magnified representation of the organic constituents of the dust of his room; and 
as if the insect-leg, with its fine hairs and claws, which had remained miracu- 
lously unhurt in pulverizing the stone, was evidently no part of the semi-opal, 
_ but rather a part of a small Acarus from the dust of the object-table, or from 
ie not quite pure water which M. Turpin employed for moistening. I have, 
moreover, never been able to go the length of recognising the egg-shells of In- 
fusoria, in the sense of Turpin (of Polygastrica). This is not the way to examine. 
ie since deceased active and talented author has deserved gratitude in other 
branches of natural history. Mortuo sit terra levis! 
{ Planerkalk. 
