Proceedings of Learned Societies. 153 



[We regret that we cannot, in the present number, lay before 

 our readers such a summary of the remarkable address read by 

 Professor Huxley (in the absence of the President) to the Geolo- 

 gical Society, on the 21st ult. It was in every respect a striking 

 paper, calculated to exert a powerful influence upon the thought! 

 of scientific men. We can only now advert to its masterly 

 analysis of the negative evidence by which palaeontologists and 

 others have built up many of the assumptions on which too much of 

 recent geology has been based. Mr. Huxley shows that we have 

 no reason to assume that similar formations in different parts of the 

 world were deposited at the same time, or even in the same age or 

 era. What we know is the order of superposition in stratification, 

 and something of the order of succession in the plants and animals 

 which fossil remains present to our view ; but we do not know, and 

 have no right to infer, that chalk formations or Silurian formations 

 in different countries, bear to each other any relation of contempo- 

 raneity ; nor have we any justification for assuming that we can 

 discern the beginnings of life in the oldest rocks in which organic 

 remains have been discovered. 



From this branch of his subject the learned Professor passed to 

 a consideration of the arguments that support prevalent theories of 

 development, either regarded as a progress from a general to a spe- 

 cialized structure, or as an advance from embryonic to adult forms 

 during the long course of ages. Here, as in the former case, he de- 

 monstrated the insufficiency of the data on which broad assertions 

 are very often made ; and showed that the extent of changes in the 

 organic world during past geological eras was much less than is 

 commonly asserted, and not brought about in stich an abrupt and 

 violent way. — Ed.] 



POYAL SOCIETY.— January 23. 



Influence of Physical Agents on the Development of the 

 Tadpole. — It is usually believed, in consequence of a statement by 

 Dr. Edwards, of Paris, in his work, On the Influence of Physical 

 Agents on Life, that the presence of light is necessary to the de- 

 velopment of the tadpole into the frog. In a paper read before 

 the Royal Society, Mr. Higginbottom has demonstrated the fallacy 

 of that opinion. His experiments were performed in cellars in Not- 

 tingham cut out of solid rock, not subject to any great change of 

 temperature, and into which no solar light ever enters. The lowest 

 cellar is 30 feet deep, and has a mean temperature of 51° Fahren- 

 heit. Ova just deposited were placed in the cellar on the 11th of 

 March, and on the 31st of October the first was fully developed in 

 the form of a frog ; whilst ova placed in the dark in a room at the 

 temperature of 60° Fahrenheit were fully developed on May 22nd, 

 twenty-three weeks earlier than those in the cellar ; proving that 

 the development of the ova depended on temperature, and not on 

 light. In fact, an excess of light retarded the development. 



Mr. Higginbottom attributes the failure of Dr. Edwards's expe- 



