42 



HOOKE. 



LCh. III. 



Respecting the extinction of species, Hooke was aware that 

 the fossil ammonites, nautili, and many other shells and fossil 

 skeletons found in England, were of different species from any 

 then known ; but he doubted whether the species had become 

 extinct, observing that the knowledge of naturalists of all the 

 marine species, especially those inhabiting the deep sea, was 

 very deficient. In some parts of his writings, however, he 

 leans to the opinion that species had been lost; and in 

 speculating on this subject, he even suggests that there might 

 be some connection between the disappearance of certain 

 kinds of animals and plants, and the changes wrought by 

 earthquakes in former ages. Some species, he observes, with 



freat sagacity, are ' peculiar to certain places, and not to be 



found elsewhere. If, then, such a place had been swallowed 

 up, it is not improbable but that those animate beings may 

 have been destroyed with it ; and this may be true both of 

 aerial and aquatic animals : for those animated bodies, 

 whether vegetables or animals, which were naturally nourished 

 or refreshed by the air, would be destroyed by the water/ &c* 

 Turtles, he adds, and such large ammonites as are found in 

 Portland, seem to have been the productions of hotter countries; 

 and it is necessary to suppose that England once lay under the 

 sea within the torrid zone ! To explain this and similar phe- 

 nomena, he indulges in a variety of speculations concerning 

 changes in the position of the axis of the earth's rotation, ' a 

 shifting of the earth's centre of gravity, analogous to the 

 revolutions of the magnetic pole/ &c. None of these conjec- 

 tures, however, are proposed dogmatically, but rather in the 

 hope of promoting fresh enquiries and experiments. 



In opposition to the prejudices of his age, we find him 

 arguing against the idea that nature had formed fossil bodies 

 ' for no other end than to play the mimic in the mineral 

 kingdom ; ' — maintaining that figured stones were c really the 

 several bodies they represent, or the mouldings of them 

 petrified/ and ' not as some have imagined, " a lusus nature, 

 sporting herself in the needless formation of useless beings/ f 



* Posth. Works, p. 327. 

 f Posth. Works, Lecture, Feb. 15, 

 1688. Hooke explained, with consider- 



able clearness, the different modes 

 wherein organic substances may become 

 lapidified; and, among other illustra- 









