CHAPTER XXIX 



LABELING AND CATALOGUING PREPARATIONS 



THE LABEL 



The first thing to write upon a label is the genus and species of the 

 plant; the next thing would be the name of the organ or tissue, and 

 then might be added the date of collection, e.g., Marchantia poly- 

 viorpha, young archegonia, January 10, 1915. The date of making the 

 preparation is of no value unless the student is testing the permanence 

 of stains or something of that sort. It is hardly worth while to write 

 upon the label the names of the stains used, for the student will soon 

 learn to recognize the principal stains. A hasty sketch on the label will 

 often indicate any exceptionally interesting feature in the preparation. 

 To facilitate finding such a feature, it is a good plan to mark the par- 

 ticular section or sections with ink, or better, with a diamond or car- 

 borundum point, the marking being always on the underside of the 

 slide so as not to cause any inconvenience if an immersion lens should 

 be used. 



Where there are 2, 3, or more rows' of sections on a slide, a desirable 

 feature may be found very quickly by marking on the label, 2d row, 



4th etc. 



' ' CATALOGUING PREPARATIONS 



As a collection grows, the student will need some device for locating 

 readily any particular preparation. Some have their slides numbered 

 and catalogued, but all devices of this sort are too cumbrous and slow 

 for the practical worker in the laboratory. After forty years' experi- 

 ence with a collection which now numbers more than thirty thousand 

 preparations, we recommend the following system : 



Four wooden slide boxes of the usual type will do for a beginning; 

 they should be labeled: Thallophytes. Bryophytes, Pterido- 

 PHYTES, and Spermatophytes. As the collection grows and new boxes 

 are needed, the classification can be made more definite, e.g., there 

 should be a box labeled Bryophytes Hepaticae and one labeled Bryo- 

 phytes Musci. As the liverwort collection grows, three boxes will be 

 necessary, and should be labeled Bryophytes Hepaticae Marchanti- 

 ales, Bryophytes Hepaticae Jungermanniales, and Bryophytes He- 



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