1706 Journal of Applied Microscopy 



globin stains, yet none is specific. If a positive result is obtained by using 

 orange-eosin, it is not certain that all the substance so stained is hemaglobin ; 

 moreover, a lack of blood material is not necessarily made evident by stains. 

 The fixative used is an important factor in the preservation of hemaglobin. To 

 study erythroblasts, the most essential elements in bone marrow, especially to 

 study the nucleus and the hemaglobin contents of the protoplasm, the investiga- 

 tion must be made on marrow from recently killed animals. The marrow of the 

 normal dog is grey-red, fatty, easily crumbling ; shows microscopically very much 

 fat. In regeneration stages it is compact, markedly harder, free from fat, and 

 deep wine-red. Marrow was taken from the epiphysis of the femur and cylin- 

 drical pieces were cut from the split long bone ; hence decalcification was 

 avoided. For preserving blood degeneration and regeneration material these 

 mixtures were used : formol-salt solution (ten to fifteen per cent, formol in five 

 per cent, salt solution) and formol-sublimate-acetic salt solution. (Formol and 

 sublimate three to five per cent., acetic acid 0.5 per cent.) Formol is invaluable 

 for all work concerning hemaglobin since the formaldehyde makes with it a met- 

 hemaglobin-like substance of great permanency. This substance has a darker 

 color than hemaglobin itself, so that the red blood cells appear more distinctly 

 marked than in fresh preparations. The second fixative is particularly good for 

 degenerating finer structures, as granules and nuclear figures. The liquid is 

 warmed to blood heat and kept in the oven at 37.5° until the fluid has pene- 

 penetrated to the middle, requiring two to three hours. Longer contin- 

 uance will make the tissue brittle and stain badly. Then follows twenty-four hours' 

 washing in running water, hardening in increasing strengths of alcohol from fifty 

 per cent, upward. Removing of sublimate by iodine-alcohol and imbedding in 

 chloroform-paraffin complete the steps. For the formol process ten per cent, is 

 used for twenty-four hours, this gives the best results with granules, mitoses and 

 plasma carrying hemaglobin. Staining followed in alum-carmin or alum-cochi- 

 neal, hematoxylin or hematein (Mayer's haemalum). A protoplasmic stain is 

 necessary, and haemalum-orange was found to be a good combination, since 

 orange brings out clearly the principal blood elements. In demonstration of 

 the finer structure Ehrlich-Heidenhain-Biondi's triple stain gave the best results. 



A. M. c. 



Herport.K. Die Reifung und Befruchtungdes Von Rath's picro-osmic-platinic chlor- 

 Eies von Petromyzon fluviatilis. Arch. f. ide-acetic mixture and picric-platinic 

 mikros. Anat. 57: "id-Qi;, iqoo. i i • i • i i- 



chlonde-acetic or aceto-sublimate were 



used for fixation. The eggs were imbedded singly in paraffin to ensure their 

 orientation. Heidenhain's iron-hematoxylin, with and without eosin, and Dela- 

 field's hematoxylin together with fuchsin and saffranin gave excellent results. 

 Eggs preserved long in alcohol cut very badly and gave almost unusable prepa- 

 rations. A. M. c. 



