48 METHODS OF STl' 



will probably be found, and it will not represent the true relations 

 of parts. Do not draw everything that can be seen, but place on 

 paper enough to represent accurately the general outline and 

 minute structure of the object that is being studied. Let the 

 relations of the parts drawn be so clearly indicated that a correct 

 picture of the object can be perfectly formed in the mind from the 

 drawings. The first drawing should usually be an outline sketch 

 of the whole object that is being studied. Then should follow 

 a more detailed drawing of each particular part as examined, and 

 lastly, the minute structure of any special tissue or cell. It is true 

 that such detail will require much time but practice will soon 

 reduce this and make the work seem very easy. It is not best to 

 shade any of the drawings since it may obscure the parts that 

 should be kept prominent. Often in studying the minute structure 

 of some organ, a single section will not give a complete outline of 

 the whole part that is to be represented, in which case, it should 

 be made up from the several sections that will best show the parts 

 desired. Be certain, however, that, the relations of parts are 

 thoroughly understood and correctly represented. One is often 

 inclined to make the drawings too small but this should be guarded 

 against, and the sketches made of sufficient size to enable the 

 parts to be clearly seen without close scrutiny. The drawings can 

 be made free-hand or by the use of a camera lucida. The latter 

 method is necessarily the more accurate but lacks much of the ele- 

 ment of good training given by the former. If the drawings are 

 made with a camera lucida, much of the detail will need to be filled in 

 free hand, but the general outline can be made with great ease. The 

 best camera lucidas are of the Abbe pattern which can be used with- 

 out tilting the tube of the microscope. With it, some difficulty 

 may be experienced in seeing the object and pencil point at the 

 same time, but this can be overcome by having the paper equally 

 illuminated with the object under the microscope. Other camera 

 lucidas may be used but it is not necessary to outline the working 

 of each in these directions. With the Abbe camera lucida, be cer- 

 tain that the drawing paper is at right angles to the axial line as 

 reflected from the mirror, otherwise the drawing will be distorted. 

 The variation a from perpendicular with the table can be deter- 

 mined by the use of a semi-circular protractor, which will give the 



