25fi Use of the Suivres in the Shilh of Animals. 



The sensible effect of the union of all these insensible com- 

 motions is sound. I confess that these ideas of M. Rilter 

 appear contradictorv to all the received opinions on the organ 

 of hearing ; hut it must also be confessed that our knowledge 

 of all the organs of sense is as yet imperfect. I am of 

 opinion, however, that the theory of M. Ritter agrees per- 

 fectly well with the anlicnt hypotheses. As for my own 

 experiments, they may be easily repeated by any person, and 

 some one perhaps may discover more than I have here de- 

 scribed. 



XLIX. On the Use ef the Sutures in the Skulls of Ani- 

 mals. By Mr. h. GiBSoa*. 



jLhe full use of the singular junction of the bones of the 

 skull which is called suture, has, from the earliest periods of 

 anatomy and suraerv, attracted the attention and eluded the 

 researches of the physiologist. To this remarkable feature 

 in osteo""eny, in a great measure peculiar to a certain period 

 of life, many uses have been attributed. Some of these are 

 totally erroneous ; such as that for allowing the transpiration 

 of moisture, to keep the brain cool and fit for thinking ; for 

 giving a more strict adhesion of the dura mater to the inner 

 surface of the skull ; for admitting a more free communica- 

 tion by blood-vessels between the t-xternal and internal parts 

 of the head ; or for affording interstices, that the bones may 

 be pushed asunder bv the growth of the brain, lesf that or- 

 gan should be cramped in its growth, in consequence of the 

 comparatively slow growth of the bones of the skull. 



Other uses attributed to the sutures are merely slight ad- 

 vantages derived from their structure, which are enjoyed in 

 early infancy, or till adult life, but gradually cease after that 

 period. Thus at the time of birth the loose union of the 

 bones of the skull accommodates the shape of the head to the 

 fioure of the differen. parts of the cavity through which it 

 passes. At adult age, when the sutures are fully formed, 



• From Mantheiltr Transactions, second scrici, vol. i. 



they 



