The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee.

  • Lee, Arthur Bolles, 1849-1927.
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    31/448 (page 13)
    ■whole of the rods and cones will be found perfectly preserved after twenty-four hours' time, and the nerve-fibres will be found not to be varicose. After this preliminary hardening, portions of the retina may be treated with water (which would be ruinous to the structures of a fresh retina), they may even remain in water for days without harm; they may be stained, acidified, hardened, imbedded, cut into sections, and mounted in either aqueous or resinous media without suffering. For the study of the intimate processes of segmentation of ova, and division of cells generally, it is evident that the employment of fixing agents is a necessity; for it is a princi- pal object of such study to seize upon particular moments of very transient phenomena, to investigate structural arrange- ments that exist only during a fleeting instant of cell-life, and that vanish without leaving a trace behind if the cells are allowed to die off slowly. The researches of Fol on the phenomena attending the impregnation of the ovum, and of Flemming and Strasburger on the division of cells and nuclei, could not have been carried out without some means of quickly rendering permanent the transient states it was desired to study. Fixing agents, then, afford a means of preserving a record of moments of vital activity that would othei-wise be inacces- sible to observation. They also afi'ord a means of seizing on transient states of functional activity, and preserving them for leisurely study. Eanvier wished to investigate the rela- tions of the different parts of muscle substance in the different stages of contraction and relaxation of the muscle. Study of the living muscle would not suffice, as it is impos- sible to follow with the eye the rapid changes by wliich a muscle passes from the state of contraction to that of relaxa- tion or the reverse. By tbe injection of a drop of osmic acid, muscular tissue is instantly fixed in the form it has when the acid comes into contact with it, and specimens of muscular