MANUAL 



OF THE 



HISTOLOGY AND HISTOCHEMISTRY OF MAN. 



INTEODUCTION 



THROUGH the industry and perseverance of many talented investigators, 

 human anatomy, as a science, had already reached an advanced stage of 

 development so early as the close of the last century. As far as the 

 dissecting knife could open up the structure of parts, these had been 

 investigated in a manner sufficiently detailed for the requirements of the 

 practical physician. And let us here offer the easy tribute of remem- 

 brance to the name of Sdmm&rri-ng, which will ever be connected with 

 this particular branch of study. That progress in development to be 

 observed in all branches of natural science as a consequence of one of 

 the nobler characteristics of human intellect, had also become manifest in 

 anatomy. Out of a multitude of isolated facts general principles had 

 been established. Anatomists had begun to recognise the significance of 

 the occurrence over and over again, in the most dissimilar parts of the 

 body, of certain definite structures, such as bone, cartilage, muscle, and 

 nerves, but slightly or not at all modified in each, though taking a most 

 important part in their formation. Here then, we have the origin of 

 " GENERAL ANATOMY," the study of the structure of the body. 



But again, bones, cartilages, muscles, and nerves were observed each 

 to be made up of smaller parts, and it became necessary to resolve them 

 into those ultimate elements of form of which they are composed, in such 

 a manner as to be able to recognise the latter in various situations. 

 Thus .the conception of an "animal tissue" originated, and with it the 

 consideration of tissues, or " HISTOLOGY," as a special branch of anatomical 

 study. This, although the most important part, constitutes by no means 

 the whole of general anatomy. 



By tissues we understand organic masses, in so far as they are made 

 up of more minute parts, and receive from these their physical, chemical, 

 anatomical, and physiological characters. 



The various arrangement and nature of these minute parts gives rise 

 to the difference in what is termed the "texture" of the mass; they 

 themselves , are known as " tissue elements." But these constituents of 

 form, these particles composing the tissues, are, in the marvellous con- 



