276 Scientific Intelligence. 
animal matter. ‘This detritus was prepared for microscopical investi- 
gation by the usual process with Canada balsam; and several examples 
of the remains of the integumentary structure of rotalia were found, 
as perfect as insects in amber; even the ova remained in-some.exam- 
ples; and in all, the connecting intestinal tube, with the little stomachs 
or sacs, the latter containing a brown granular substance, were preser- 
ved. Dr. Mantell has sent a communication on the silynct to the Roy: 
al Society. 
6. Boring power of Lind. Snails on Luhatsioad by W. re Tanusil 
yan, (Jameson’s Edinb. Jour., xl, 1846, 396.)—Few persons are, I be- 
lieve, aware of the fact, which I alluded to at the meeting of the British 
Association in Cambridge last year, on the occasion of a notice by Dr. 
Buckland, “On the agency of land snails in forming holes and track- 
ways in compact limestone,” that this phenomenon had been noticed 
many years ago by the late amiable and talented author of the History 
of Northumberland, the Rev: John Hodgson, an accurate observer of 
nature, who, in 1827, published in that work (part 2, vol. i, p. 193) the 
following passage :—“ On a sunny bank near Whelpington, a stratum 
of limestone’”’ (carboniferous) ‘ is.here and there seen in gray project- 
ing masses, the under surface of which is bored upwards into cylindri+ _ 
cal holes, which are from a line to four inches deep, and tenanted, espe- 
cially in winter, by the banded and yellow varieties of the Helix nemo- 
ralis. The limaz, while it occupies these cavities during summer, has 
its fleshy longitudinal disk protruded out of the shell, and coiled nearly 
into a circle on the surface of the stone, the summit of its shell hanging © 
downwards; and in this position it probably elaborates: its den in the 
same manner that some of the pholades work: their way into clay and 
wood, or, by a slow but constant process, sink and enlarge their cells in 
the hardest stones.”? I had, sometime previously to the date of this pub- 
lication, examined the spot, and was satisfied with the correctness of Mr. 
Hodgson’s observations, and last October, (1845) took advantage of an 
‘opportunity to revisit it, and was confirmed in the opinion I had before 
formed on the subject, and in the perfect accuracy of the ae 
quoted above 
The shied sheltered position of the under pa ane of the rock 
precludes the possibility of the holes being an effect of weathering} 
and I feel convinced that they are the result of the slow, but nearly 
constant action, of a weak acid secreted by the snails, which instine- 
tively, for the sake of shelter, would resort to such a situation, and 
in the course of ages, such holes would: be eran te wy 
ae: on which the obiik ‘eould. act. 
i the Blood ; oy Dr. 4. J. We 
