Royal Society. 467 



above their present level, and that a great part of Finland, Russia, 

 and Prussia bordering upon that sea, would thus every twelve hours 

 be under water, in the same way as the waters now rise in the Bay 

 of Fundy, at Chepstow, and other places, much above their ordinary 

 level in the open sea ; that the current outward, on the receding 

 of the tide which these accumulated waters would occasion, com- 

 bined with the rivers which fall into the Baltic, when checked by 

 the following flood-tide, would cause deposits in the form of a bar 

 tailing towards Sweden ; and that an increase to these deposits 

 would form shoals, drifts and islands, and eventually a long sand- 

 bank in outline, like the country of Denmark. He further considers 

 that the tide being by these means prevented from entering the 

 Baltic, may account for the subsidence of the waters of the Gulf of 

 Bothnia better than can the upheaval of the northern part of Scan- 

 dinavia. 



The author then remarks that the great shoal of the North Sea is 

 the Dogger Bank, and that its peculiar form is produced by the 

 meeting of the cotidal waves, of which he traces the course. After 

 bearing testimony to the value of the Admiralty chart of the southern 

 portion of the North Sea, made under the direction of the late Cap- 

 tain Hewitt, he reverts to the importance of contouring such maps, 

 in order to obtain something like a correct notion of the bottom of 

 the sea ; and in conclusion expresses a hope that the Admiralty will 

 be induced to continue the survey of the North Sea, so well begun 

 by Captain Hewitt. 



June 10. — The following papers were read: — 



" On the Structure and Development of Bone." By John 

 Tomes, F.R.S., Surgeon Dentist to the Middlesex Hospital, and 

 Campbell De Morgan, Surgeon to the Middlesex Hospital. 



In this communication, the authors, after having briefly noticed 

 the intimate structure of perfect bone as commonly recognised, pro- 

 ceed to the description of certain points connected with its structure 

 and development, which they believe to have been hitherto entirely 

 overlooked or only partially recognised. 



These points have been arranged under the following heads : — 



1. The Haversian and other canals of bone, 



2. The laminae of bone. 



3. The lacunae. 



4. Haversian systems. 



5. Ossified cartilage of joints. 



6. Ossified cells. 



7. Bone tissue. 



8. Development of bone in temporary cartilage. 



9. Growth of bone. 



1. Haversian and other canals of bone. — Besides the Haversian 

 canals, the authors have pointed out that there are found in bone 

 sections spaces of an entirely diflfierent character, irregular in shape, 

 and with an irregular festooned margin. Their margins correspond 

 in outline with those of one or more Haversian systems, and precede 



2 II 2 



