376 
NATURE 
[ Sez. 8, 1870 
I should have known exactly what he meant, and made bold to 
differ from him. 
I feel sure, however, that those geologists who have endea- 
voured to revise the almost forgetten teaching of Hutton as to 
the important part played by siibaérial denuding forces in forming 
the present surface of the ground, are by no means forgetful of 
the obligations they are under to upheaval for furnishing them 
with materials to be shaped; «nd in cases of great mountain 
chains they have always admitted that the superior elevation of 
the ground is mainly due to internal action, though they hold 
that all the sculpturing of the upheaved mass into gorge and 
peak is due to atmospheric agency. A. H. GREEN 
79, Dodworth Road, Barnsley, Sept. 3 
Geology of Devonshire 
A RAILWAY of eight or tenmiles is now in course of construction 
between Totnes and Ashburton in Devonshire. To a geologist 
the cuttings near the latter town are most interesting. Iam nota 
geologist, although the science is deeply interesting to me. I 
returned from Ashburton ten days ago. The rocks there at 
one part of the line were evidently volcanic. They appear 
exactly as if they had been melted, and in boiling up a scum or 
froth had risen on the surface, and in cooling had left air-bubbles, 
now nearly filled with sometimes yellowish crystals. The rock 
is very hard, and has a stratum of what was once slate, ten or 
twelve feet thick, and as the workmen work it out it bears the 
colour which great fire would give it. As blocks of the other 
rock are torn out by powder, they are found to contain or enclose 
fragments several inches square of the superincumbent slate rock, 
too hard to be melted. ‘This rock is not stratified, but breaks 
into any form. A few hundred yards off they are working 
through ironstone as hard as iron itself. The heavy sledge 
hammer rings on the blocks as on an anvil. At the east end of 
the town are two pits worked for umber, indeed there are several 
fields of which the soil a few inches below the surface consists 
wholly of umber. I do not expect there is any one in the neigh- 
beurhood who fecls an interest in geology. I saw a letter in 
NATURE on a geological subject from Mr, Pengelly, of Torquay 
and I wrote him on the above subject. I have no doubt the line 
is very interesting in the other parts, as the rocks greatly vary 
thereabouts. 
A learned geologist would have made what I have attempted 
to describe more interesting. He would find much to employ 
him in that neighbourhood, W. LuscoMBE 
Hereditary Deformities 
In the lessons in Ethnology in ‘‘ Cassell’s Popular Educator,” 
it is stated, on the authority of Dr. Theodor Waitz, and the 
Secretary of the Anthropological Society, that ‘‘an officer, whose 
little finger had accidentally been cut across, and had, in con- 
sequence, become crooked, transmitted the same defect to his 
offspring. Another officer wounded at the battle of Kylau, had 
his scar reproduced on the foreheads of his children.” And 
again, ‘‘In Carolina, a dog which had accidentally lost its tail 
transmitted the defect to its descendants for three or four genera- 
tions.” Do these stories rest on a good foundation? We know 
that congenital peculiarities of form and disposition are trans- 
mitted from parent to offspring, but that an accidental de/ormity 
should be so transmitted is a very different affair, and if substan- 
tiated would introduce Accrden/al Distortion as a co-worker with 
natural selection in the modification of species. 
Faversham, Kent, Aug. 27 WM. Fiei_p 
Poisoning by C£nanthe crocata 
PERMIT me to send you the following notes with regard to the 
case of poisoning by (zanthe crocata which appeared in your 
issues of 18th August and Ist September. 
1. As to the poisonous properties of 2zanthe, Prof. Christison 
found that plants gathered in certain localities were harmless, 
while others from different places were highly poisonous. 
11. As to the mode of death. This seems materially to differ 
from that observed and recorded with regard to poisoning with 
hemlock (Coziaum maculatum). In the case of poisoning with 
hemlock which took place in I*dinburgh in 1845 (recorded in the 
Edin, Med, and Surg. Fournal, No. 164, and also Prof. Bennett’s 
“*Principles and Practices of Medicine”) the mind remained clear 
till the end, and death resulted from asphyxia produced by slow 
paralysis of the muscles of respiration. 
commenced in the feet. 
In the recent case of poisoning by @xanthe there seems to 
have been coma and convulsion for half an hour previous to death; 
no paralysis seems to have occurred over the body. From the 
account of the hemlock case to which I have referred, that plant 
also seems not to have any particularly acrid taste. The part 
that seems strange to me is the difference in the mode of death 
with plants so nearly allied to each other as the @nanthe and 
the Conium. J. W. E.j EpIn. 
The muscular paralysis 
NOTE ON SOME INSTANCES OF PROTECTIVE 
ADAPTATION IN MARINE ANIMALS 
HE various phenomena of mimicry and protective 
adaptation have recently received much attention, 
notably from Messrs. Darwin, Bates, and Wallace, and 
some very interesting facts.and reasonings onthe subiect are 
contained in the recently published “ Contributions to the 
Theory of Natural Selection” by the Jast-named author, 
It can scarcely be needful to explain at much length the 
nature of the phenomena in question. Well-marked 
instances of mimicry are not very common ; some of the 
most surprising are those of the leaf and stick insects of 
the Tropics, which it is almost absolutely impossible, 
when at rest, to distinguish from dead leaves and twigs. 
The importance of these resemblances, in conferring pro- 
tection from attack, will be at once evident. Commoner 
instances of adaptation, which may indeed be noticed 
wherever we turn our eyes upon the animal creation, are 
those of more or less complete resemblance of colour 
between the animal and its surroundings. The most 
remarkable instance of this kind which has come under 
my own observation is perhaps that of the caterpillar of 
the Emperor moth (Saturnia favonia minor), which, with 
its green ground and brilliant pink spots, is almost undis- 
tinguishable from the heather upon which it frequently 
feeds. 
Numerous instances ot this kind amongst terrestrial 
animals might be brought forward, but less attention has 
been paid to similar points in the less highly-organised of 
marine animals. They are, for the most part, much less 
easily observed in their natural haunts, and their habits and 
the dangers to which they are exposed are of necessity 
imperfectly understood. We may note, however, that 
fishes very commonly assume the colours of surrounding 
objects ; the flounder is almost exactly of the colour of 
the sand on which it lies, and fishes which bask amongst 
groves of seaweeds are often of brilliant and variegated 
colours corresponding very much with the vegetation 
around them, 
The two instances which form the subject of this 
notice came under my observation while dredging in 
June last in the Frith of Clyde. In one spot the 
dredges brought up many plants of Lamnari@ with 
their roots, which consist of a conical mass of contorted 
and intertwined fibres about a line or two in diameter ; 
amongst these were imbedded quantities of nullipores— 
a calcareous seaweed of the genus Melobesia—(JZ. ca/- 
carea). The larger weed had, in fact, grown in a bed of 
the nullipore, which came up abundantly in the dredge, 
and indeed now forms on a closely adjacent part of the 
coast a raised beach of several feet in thickness. Amongst 
the nullipore which matted together the laminaria roots 
were living numerous small starfishes (Ofhzocoma bellis), 
which, except when their writhing movements betrayed 
them, were quite undistinguishable from the calcareous 
branches of the Alga; their rigid, angularly-twisted rays 
had all the appearance of the coralline, and exactly assi- 
milated to its deep purple colour, so that though I held in 
my hand a root in which were half a dozen of the star- 
fishes, I was really unable to detect them until revealed by 
their movements. 
