The origin and development of the wings of Coleoptera. 565 



After killiag dehydrate rapidly, clear in cedar oil and preserve 

 in paraffine. If the tissues are to be kept in alcohol remove the 

 sublimate with iodine in 70 "/o alcohol and preserve the tissue in 

 80 — 85 "/o, I find, however, that insect tissue soon loses its finer 

 structure in alcohol and becomes more difficult to section. 



In preparing tissues where there was much chitin I found it 

 impossible to remove or soften the chitin without injuring the tissue 

 so seriously as to destroy the value of the sections. With proper 

 fixation, careful imbedding, sharp knifes and patience I have been 

 able to get good series of sections of hard chitinous structures. 



Hull Zoological Laboratory 

 University of Chicago, Dec. 1, 1901. 



