of the President of 



249 



oped as the teeth, which formed the subject of Professor Owen's com- 

 munication in 1838, and as the external coverings of the testaceous 

 mollusca, which formed the subject of Dr. Carpenter's communication 



in 1846. 



11 The structure of the softer tissues of the animal frame has not been 

 less successfully investigated by microscopic observers. One of the 

 most extraordinary, perhaps, of the recent discoveries by the micro- 

 scope is that which is due chiefly to Purkinge and Valentin, and which 

 in this country has been well established by Dr. Sharpey, relative to 

 the important part in the motion of fluids on internal surfaces, perform- 

 ed by the vibratile action of myriads of extremely minute hairs or cilia 

 which beset those surfaces. These ciliary movements, for example, 

 raise the mucus of the wind-pipe to the throat against gravity. They 

 have been detected in the ventricles of the brain, as well as many 

 other parts. 



w Microscopic anatomy has been chiefly indebted to Ehrenberg, 

 Remak, and Dr. Martin Barry, for the exposition of the ultimate 

 structure of the nervous and cerebral fibres. 



"Exact knowledge of the nature of the retina, or the vitreous and 

 crystalline humors, and of other delicate constituents of the organ of 

 vision— the most wonderful of all the organs with which God has en- 

 trusted man — has been remarkably advanced by the skilful use of the 

 improved microscopes of the present day. I rejoice that, among the 

 proposed arrangements of the Association at its present meeting, one 

 evening, Tuesday the 29th, will be specially devoted to an exhibition 

 °f microscopic objects. The beautiful discoveries of Sir David Brew- 

 ster (whom, in this Association, we must always mention as one of our 

 earliest friends and patrons, three times one of our Vice Presidents,) 

 have been carefully confirmed ; and many interesting varieties have 

 been noticed in the structure of the crystalline lens of the eyes of dif- 

 ferent species of animals. 



"The most brilliant result, perhaps, of microscopic anatomical re- 

 search has been the actual observation of the transit of the blood from 

 the arteries to the veins ; the last fact required— if, indeed, such an ex- 

 pression be allowable— for the full proof of Harvey's doctrine of the 

 ^culation of the blood. Malpighi first observed the transit in the large 

 capillaries of the frog's web. Ft has since been observed in most other 

 'ssues, and in many^other animals. 



'No part of the animal body has been the subject of more, or of 

 m °re successful, researches than the blood itself. The forms and di- 

 me nsions and diversities of structure characteristic of the colored discs, 

 Cor puscles, or blood globules, as they were once termed, in the differ- 

 J nt classes, orders, and genera of animals, have been described, and 

 7 Ae most part accurately depicted ; and through the concurrence 

 ^numerous observers, the anatomical knowledge of these minute par- 

 ttc, «*i invisible to the naked eve, has become as exact and precise as 

 ine knowledge of the blood vessels themselves, or of any other oi the 

 josser and more conspicuous systems of organs; and has added,- 

 wh *n we consider how easily the action is deranged, by how man 

 ' aus es it may be diseased or stopped,— another to the many proofs that 

 We are fearfully as well as wonderfully made. In surveying how our 



Sec oxd S£r, es> Vol. IV, No. ll.-Sept., 1847. 32 



