296 Journal of Applied Microscopy. 



have a lens with which a power as high as one hundred diameters can be 

 obtained. 



]5alsam is a very unsatisfactory mounting medium for copepods, and I use 

 ahiiost exckisively for this purpose Farrant's medium. The parts as dissected 

 in glycerine can be removed directly to this medium. If one is careful to spread 

 out the drop of Farrant's on the slide in a thin layer, the parts can be placed in 

 order, and the cover-glass put upon them with very little disturbance of their 

 relative positions, and it is not necessary to use anything to fix their positions 

 on the slide. 



The covers can be ringed with any good cement. I use mostly Brunswick 



black. The shrinking of the Farrant's will sooner or later cause the cement to 



crack, so that it is necessary to ring them again after some months, if the 



preparations are to be kept permanently. The preparations do not suffer, 



however, if this second ringing is neglected, as the Farrant's hardens, and the 



preparations will keep perfectly except as they are subject to "hard usage. 



C. DwiGHT Marsh. 

 Ripon College, Wis. 



METHODS IN PLANT HISTOLOGY. 



Charles J. Chamberlain. 



I. 



During recent years the microscope has been finding its way into a con- 

 stantly increasing number of schools, colleges, and homes, and, as might be 

 expected, there has been an increasing demand for better methods of preparing 

 material for microscopic study. The earlier investigators examined objects in 

 the dry condition and without cover glasses. If a thin piece of pine shaving be 

 examined dry, it shows some structure, but it shows more if wet with a drop of 

 water and covered with a cover-glass, and it shows infinitely more if properly 

 stained and mounted. 



It is the purpose of this series of papers to present the current methods of 

 preparing botanical material for microscopic examination, and in presenting the 

 subject we shall try to meet, as nearly as possible, the needs of the amateur, the 

 teacher, and the student engaged in research work. Methods will be described 

 for mounting all kinds of material, from the lowest alg.x to the highest flowering 

 plants, but the order in which the methods are taken up will be governed erjtirely 

 by the comparative difficulties of the technique, it being assumed that the reader 

 is a beginner. While very few of the methods are original with the writer, it is 

 nevertheless true that the descriptions are based upon a somewhat extensive 

 experience in laboratory work with beginners and with advanced students. 



After a brief mention of the apparatus and reagents needed for the work, 

 attention will be given to the various methods of killing, fixing, hardening, 

 dehydrating, imbedding, sectioning, staining, mounting, drawing, etc. The 

 paraffine method and staining will receive particular attention. 



