1888-89.] The Duke of Argyll on Bodies of Organic Origin. 59 
deformation to which these may have been exposed by crushing or 
slipping movements in the rock. In the tenth place, in cases where 
the tubes have been exposed to the solvent action of sea-water, or, 
in other words, to weathering on a sea-beach, and where, conse- 
quently, all the special products due to the chemical and mechanical 
and vital action of the worms have been excavated and removed, we 
should expect to find the sides of the cavity thus left presenting a 
peculiar coarsely granular surface, from the old abstraction of the 
finer and the more argillaceous particles which the worm had 
swallowed and ejected in a comparatively loose and incoherent 
state. In the eleventh place, as our living annelids are various, 
and produce variously shaped burrows, we should expect to find 
some worm-paths less simple and less easily recognised than others, 
— such, for example, as irregularities, bunches or knots, bays, and 
branches in the path, — or perhaps such definite and characteristic 
varieties as club-shaped burrows, which are now actually produced 
by some living species.* 
I have placed on the table to-day specimens from the Inveraray 
quartzite which fulfil and illustrate every one of these anticipations. 
The prevalence of ovate forms wherever we have cross sections of the 
old planes of bedding; the narrowing or elongation of these ovate 
forms in proportion as the section is oblique to the bedding; the 
reduction of these to mere linear streaks w T here the squeezing of 
the rocks seems to have been greatest; the altered character of the 
matter which occupies the interior of the ovate spaces, where 
metamorphism has not gone far — all these characters are beautifully 
marked. The conversion of the same material into shining mica, 
where metamorphism has been more advanced, is not less striking. 
In some of the specimens the brilliancy of the silvery mica, 
especially when seen in sunlight and with a lens, traces out the 
ancient worm paths with extraordinary distinctness. The oval 
rings of oxide of iron, which indicate the transverse sections of 
the tubing, is one of the most marked characteristics, of one at least, 
of the beds. The coarse granulations of the rock, in cavities out of 
which the worm-work has been excavated by the sea, is typically 
exhibited in the only specimen which has been found under 
exposure to the necessary conditions ; whilst there is one specimen 
* Mackintosh, Mag. Nat. Hist., 1888, p. 12. 
