54 INTRODUCTION. 



thus pursued gradually becomes to him an object of such attrac- 

 tive interest, that he experiences a zest in its pursuit to which the 

 mere dilettante is au entire stranger, — besides enjoying all the 

 mental profit, which is the almost necessary result of the thorough 

 performance of any task that is not in itself unworthy. Aiid 

 what can be a more worthy occupation, than the attempt to gain 

 an insight, however limited, into the operations of Creative 

 Wisdom? — these being not less wonderfully displayed among 

 the forms of Animal life which are accounted the simplest and 

 least attractive, than in those which more conspicuously solicit the 

 attention of the Student of Nature, by the beauty of their aspect 

 or the elaborateness of their organization. 



It has not been, however, in the study of the minuter forms of 

 Animal life alone, that the Microscope has been turned to valu- 

 able account; for the Anatomists and Physiologists who had 

 made the Human fabric the especial object of their study, and 

 who had been led to believe that the knowledge accumulated 

 by their repeated and persevering scrutiny into every portion 

 accessible to their vision, was all which it lay within their power 

 to attain, have found in this new instrument of research, the 

 means of advancing far nearer towards the penetralia of Organ- 

 ization, and of gaining a much deeper insight into the mysteries 

 of Life, than had ever before been conceived possible. For 

 evei-y part of the entire organism has been, so to speak, decom- 

 posed into its elementarg tissues, the structure and actions of each 

 of which have been separately and minutely investigated ; and 

 thus a new department of study, which is known as Histology (or 

 Science of the Tissues), has not only been marked out, but has 

 already made great advances towards completeness. In the 

 pursuit of this inquiry, the Microscopists of our day have not 

 limited themselves to the fabric of Man, but have extended their 

 researches through the entire range of the Animal kingdom; 

 and in so doing, have found, as in every other department of 

 [N'ature, a combination of endless variety in detail, with a mar- 

 vellous simplicity and uniformity of general plan. Thus the 

 hones which constitute the skeleton of the Vei'tebrated animal, — 

 however different from each other in their external configura- 

 tion, in the arrangement of their compact and their cancellated 

 portions, and other such particulars as specially adapt them for 

 the purposes they have to perform in each organism, — all consist 

 of a certain kind of tissue, distinguished under the microscope 

 by features of a most peculiar and interesting kind ; and these 

 features, whilst presenting (like those of the Human counte- 

 nance) a certain general conformity to a common plan, exhibit 

 (as Prof. Quekett has shown) such distinctive modifications of 

 that plan in the different classes and orders of the Vertebrated 

 series, that it is generally possible by the microscopic examina- 

 tion of the merest fragment of a bone, to iironounce with great 

 probablUty as to the natural family to which it has belonged. ^Still 



