IV PREFACE. 



tice to those Tvlio have most claim to honorable distinction. His princi- 

 ple has been to make mention of such Makers as have distinguished 

 themselves by the introduction of any neiv pattern which he regards as 

 deserving of special recommendation; those who have simply copied the 

 patterns of others without essential modification, receiving no such recog- 

 nition, not because their instruments are inferior, but because they 

 aro not original. 



In treating of the Applications of the Microscope, the Author has 

 constantly endeavored to meet the wants of such as come to the study 

 of the minute forms of Animal and Vegetable life with little or no previ- 

 ous scientific preparation, but desire to gain something more than a 

 mere sight of the objects to which their observation may be directed. 

 Some of these may perhaps object to the general tone of his work as too 

 highly-pitched, and may think that he might have rendered his descrip- 

 tions simpler by employing fewer Scientific terms. But he would reply 

 that he has had much opportunity of observing among the votaries of the 

 Microscope a desire for such information as he has attempted to convey; 

 and that the use of scientific terms cannot be easily dispensed with, since 

 there are no others in which the facts can be readily expressed. As he 

 has made a point of explaining these in the places where they are first 

 introduced, he cannot think that any of his readers need find much diffi- 

 culty in apprehending their meaning. 



The proportion of space allotted to the several departments has been 

 determined not so much by their Scientific importance, as by their special 

 interest to the amateur Microscopist; and the remembrance of this consider- 

 ation will serve to account for much that might otherwise appear either 

 defective or redundant. Thus, the Author has specially dwelt on those 

 humble forms of Vegetable and Animal life, which the diligent collector 

 is most likely to meet with, and which will fully reward his most atten- 

 tive scrutiny. And he has endeavored, in his account of them, to inter- 

 est his readers in the knowledge to be drawn from their study, as to those 

 fundamental phenomena of living action which are now universally admit- 

 ted to constitute the basis of Physiological science; thus giving to the 

 portion of his Treatise which treats of Protophytic and Protozoic organ- 

 isms, the character of a General Introduction to the study of Biology, 

 which will, he hopes, prove specially useful to such as desire to follow 

 this study into its higher walks. On the other hand, the Author has 

 felt the necessity of limiting within a narrow compass his treatment of 

 various important subjects which are fully discussed in Treatises expressly 

 devoted to them (such, for example, as the structure of Insects, and Ver- 

 tebrate Histology), in order that he might give more space to those on 

 which no such sources of information are readily accessible. For the 

 same reason, he has omitted all reference to the Embryonic Development 

 of Vertebrated Animals, a study that is second to none in scientific in- 

 terest, but can only be advantageously taken up by the Microscopist who 



