DENNIS, ON FOSSIL LIAS. 261 



The existence of Mammifers anterior to the deposition of the 

 Lias, demonstrated from the Microscopic Structure of a 

 Bone from the River-Bed Deposit, Lyme Regis. By the 

 Rev. J. B. P. Dennis, Bury St. Edmunds. (Plate XVL) 



Through the kindness of the President of the Geological 

 Societj, a Paper of mine was read before the Society on the 

 19th of March last, in which I brought under their notice 

 certain facts which seemed to me strongly to indicate the 

 existence of Mammifers at a period when the Lias had not 

 been deposited, and in a deposit well known by the name of 

 the Bristol bone-bed. Since then, through the kindness of 

 Professor Owen, Dr. J. E. Gray, and Professor Huxley, I have 

 had great opportunities of carrying on my investigations, and 

 I trust that, tliough errors may be found in my inductions, the 

 result of my inquiries will be found to have added some fresh 

 truth to tlie treasures of science. 



Being desirous of giving publicity to some of the results of 

 my labours, the Editors of the Microscopic Journal have 

 coui'teously offered me an opportunity of so doing ; and as my 

 investigations have been for the most part microscopic, that 

 journal seems the most fitting medium for the introduction of 

 my views. 



The microscope, like the telescope in another field, has 

 already revealed its wonders and unlocked many of the once- 

 hidden mysteries of Nature. No small authority has said, 

 " By the microscope the supposed monarch of the Saurian 

 tribes, the so-called Basilosaurus, has been deposed and re- 

 moved from the head of the reptilian to the bottom of the 

 mammiferous class. The microscope has degraded the Sau- 

 rocephalus from the class of Reptiles to that of Fishes." And 

 Mr. Quekett, adverting to these brilliant results of Professor 

 Owen, justly inquires, "Why should not the minute fragments 

 of the other parts of the skeletons of extinct animals afford us, 

 by the same method of manipulation, some indications of the 

 particular class to which such fragments belong?" Such 

 reasoning is irresistible : and I may mention as a corrobora- 

 tive circumstance in favour of the use of the microscope, that 

 a geologist gave me what he considered, and what I believed 

 to be the bone of a pterodactyle, but which the microscope 

 proved to be crustacean. 



In my examination of the microscopic structure of bone, I 

 have observed certain facts that have induced me to suspect 

 a law which, if I am right in the discovery, will be of great 

 importance to science. I have noticed, for instance, in ani- 



VOL. IV. T 



