Geological Survey of the Yorkshire Coast. 423 
is no enemy which it fears openly to attack, and “ none is so 
fierce that dare stir him up.” But all vitality, all muscular 
energy, depends on the act and effects of respiration ; and 
how are these habits of the crocodile to be reconciled with 
this law? On land, when breathing the atmosphere at full, 
he is sluggish and fearful; it is only when immersed in water, 
and where respiration is liable to be impeded, that he acquires 
strength, activity, and courage. ‘There is here an exception 
to the law, but it is only in appearance; and it is curious to 
remark how simply nature in this case enlarges the respiratory 
organ and function, and gives to the aquatic creature its cor- 
responding power, without deviating in any thing from the 
one model of organisation. By means of two canals, which 
take their origin in the cloacum, and which open into the 
cavity of the peritoneum, water is conveyed within the abdo- 
men to act upon the blood in its vessels ; and through the 
abdominal vessels, thus called upon to aid the lungs in oxy- 
genating the blood, the additional vigour to the muscular 
system is imparted. The crocodile has an abdominal sternum 
independently of its pectoral sternum: each sternum and its 
muscles regulate the effects of their proper and respective 
respiration. When the animal is on land, it is the thorax 
and its sternum which are only in action: when in the water, 
the abdomen and its sternal apparatus are likewise called into 
play. Isidore Geoffroy Saint-Hilaire and Joseph Martin were 
the discoverers of the canals which open into the peritoneum ; 
a discovery of great interest, as previously to it the habits of 
the crocodile were inexplicable. 
N. 
Art. Il. A Geological Survey of the Yorkshire Coast, describing 
the Strata and Fossils occurring between the Humber and the Tees, 
from the German Ocean to the Plain of York. By the Rev. 
George Young, A.M., assisted by John Bird, Artist, Members of 
several Local Philosophical Societies. Second Edition, 1828. 
Tue district which this volume is proposed to illustrate is inferior to few 
portions of our island in geological interest, as it regards what are commonly 
termed the secondary formations, or those which contain organic remains, 
from the chalk to the lias inclusive. “ Nowhere,” the authors observe, 
“have the fossil relics of animals and vegetables been found in greater 
variety and abundance. Almost every stratum teems with substances for- 
merly endowed with life and motion; and the fossil conchology of the dis- 
trict might, of itself, occupy a large volume. Hence, not only the mere 
geologist, but the student in naturai history, may here find an employment 
adapted to his taste, in comparing the recent productions of nature with 
those which have been embedded in the bowels of the earth, and which are 
fitly regarded as the medals of nature’s history.” The authors, who had 
previously occupied themselves in preparing the geological portion of The 
