2 INTRODUCTION. 



(Foutana, Muys, Lieberkuhn, Hewson, Prochaska), Histology- 

 made no considerable progress during the whole of the 18th 

 century, and acquired no importance greater than that due to a 

 disjointed collection of isolated observations. It was in the 

 year 1801 that it first acquired a rank co-equal with that of its 

 sister anatomical sciences, by the genius of a man to whom 

 indeed, Histology owes no great discoveries, but who under- 

 stood, as no one before him had done, so to arrange existing 

 materials and so to connect them with Physiology and 

 Medicine, that for the future its . independence was assured. 

 In fact, Bichat's ' Anatomie Generate' (Paris, 1801), was the 

 first attempt to treat Histology scientifically, and on this 

 account merely, it constitutes an epoch; but besides this, its 

 importance was still greater, inasmuch as the tissues were not 

 merely clearly defined and fully and logically treated of, but 

 full account was taken of their physiological functions and 

 morbid alterations. To this great internal progress, the 

 present century has added an ever-increasing perfection of the 

 external aids of the microscope, and a steadily increasing zeal 

 in the investigation of nature, so that it is not to be wondered 

 at, that in its five decades, it has left far behind all that was 

 done in the century and a half of its earlier existence. In the 

 last thirty years particularly, discoveries have so trodden upon 

 one another's heels, that it must be considered truly fortunate 

 that a bond of connection has arisen, and that Microscopical 

 Anatomy has thus escaped the danger of becoming, as in 

 earlier days, lost in minutise. In the year 1838, in fact, the 

 demonstration by Dr. Th. Schwann, of the originally perfectly 

 identical cellular composition of all animal organisms, and of the 

 origin of their higher structures from these elements, afforded 

 the appropriate conception which united all previous obser- 

 vations, and afforded a clue for further investigations. If 

 Bichat founded histologv more theoretically bv constructing a 

 system and carrying it out logically, Schwann has, by his inves- 

 tigations, afforded a basis of fact, and has thus won the second 

 laurels in this field. What has been done in this science since 

 Schwann, has been indeed of great importance to physiology 

 and medicine, and in part of gre^t value in a purely scientific 

 point of view, inasmuch as a great deal which Schwann only 

 indicated, or shortly adverted to, as the genesis of the cell, the 



