and Laboratory Methods. 



2115 



The illustration, from a photograph of two charts as they hang before the 

 blackboard, shows (chart A) the different types of epithelial cells, and (chart B) 

 the third day and fifth day chicks. 



The charts are kept rolled, held with elastic bands, and stacked in a case 





# « 







^ 



A 



Chart A. 



Chart B. 



built for the purpose. Each is numbered on the end of the roller, and on the 

 inside of the cover of the case is tacked a card giving each number with a list 

 of figures represented on the chart, and the name and page of the text-book 

 from which they were taken, thus forming a complete index of the illustrations 

 at hand. Martha Tracy. 



Woman's Medical College of Pennsylvania. 



A Simple Device for Carrying Minute Objects Through the 

 Grades of Cedar Oil and Paraffin. 



In preparing some pollinia of Asdepias for embedding in paraffin consider- 

 able trouble was experienced through losing quantities of the material in trans- 

 ferring from one grade of cedar oil and paraffin to another. Finally this trans- 

 fer was very successfully accomplished by enclosing the pollinia in little bags 

 made by bringing together the four corners of a small square (1.5 in. x 1.5 in.) 

 of cheese cloth, and fastening them by one or two turns of small copper wire. 

 One end of the wire was left about one inch long and hooked at the free end. 

 The little bags could be suspended by the hooks in the bottles of oil and paraf- 

 fin and easily transferred from one to another. Penetration of the tissues by 

 the paraffin was not interfered with at all by the cloth, so far as could be 

 observed. Material thus treated yielded good sections. When the last step, 

 embedding, was reached, the bags were cut from the wire, opened in the melted 

 paraffin, and the pollinia distributed as desired. By this device, excessive hand- 

 ling, which is so injurious to delicate tissue, was avoided. 

 New York State Normal College. C. StuART Gager. 



