Cited by W.B. Hardy, 'On the Structure of Cell Protoplasm: Part I', Journal of Physiology 24 (2) (1899), pp. 158-210.
Description:

Explanation of Plate III (figs. 1-20):

'Egg-white. Sections 0.6 to 1.0 µ thick cut from paraffin; stained with iron-haematoxylin. Magnified 1500 diameters; camera lucida.

Fig. 1. Solids per 100 c.c. 13 grs. Fixative sublimate.

Fig. 2. Solids per 100 c.c. 30 grs. Fixative sublimate. a. a. Carmine grains.

Fig. 3. Solids per 100 c.c. 60 grs. Fixative sublimate.

Fig. 4. Solids per 100 c.c. 13 grs. Fixative potassium sulphocyanate. Gelatine. Film preparations fixed with sublimate. Mag. 1500 diams.; camera lucida.

Fig. 5. Solids per 100 c.c. 4 grs.

Fig. 6. Solids per 100 c.c. 10 grs.

Fig. 7. Solids per 100 c.c. 25 grs.

Fig. 8. Solids per 100 c.c. 50 grs.

Fig. 9. Egg-albumen. Solids 13 grs. per 100 c.c. Film fixed by steam while flowing between two coverslips - to show abrupt transition from net region to optically homogeneous film. a, a', interior of two contiguous air-bubbles. Mag. 450 diams.; camera lucida.

Fig. 10. Gelatine droplet fixed while flowing over coverslip with sublimate. Stained with iron-haematoxylin. Note unstaining optically homogeneous edge film. Mag. 1000 diams.; camera lucida.

Orbital gland. Kitten.

Fig. 11. Fixative absolute alcohol 20 hours. Freehand sections stained with methylene blue in 90% alcohol and examined in xylol. Framework a brilliant green, shrunken remains of mucous granules a dull opaque blue. Mag. 1500 diams.; camera lucida.

Fig. 12. (a) Net in 50% spirit; intact granules swollen. Not camera lucida.

(b) Same net, after dehydration in xylol; methylene blue.

Fig. 13. Fixative osmic vapour 8 hours. Section 2 teeth (± 1.4 µ) cut in paraffin. Mag. 1000 diams.; camera lucida. (a) Appearance after removal of paraffin and mounting in 95% spirit. (b) After irrigation with lower strengths of spirit down to 30%; drawn in 30%. Section unstained.

Fig. 14. Fixative osmic vapour 24 hours. Mag. 1000 diams.; camera lucida. Section 1 tooth (± 0.7 µ). Same portion of the alveolus was drawn in each case. (a) section unstained mounted in absolute alcohol after removal of paraffin. Stained with iron-hematoxylin while on stage of microscope, brought back into xylol, drawing (b) made. Staining light. Restained with iron-hamatoxylin-ferric alum 2% 13 hours; strong haematoxylin 24 hours; staining very intense. Brought into absolute, drawing (c) made; irrigated with xylol and drawing (d) made. Illumination moderate, the condenser being achromatic. The change in the image due to the refractive index of the mounting medium is noteworthy. In (c) resolution was difficult owing to the intensity of the stain.

Fig. 15. Orbital gland. Puppy. Section 2 teeth (± 1.4 µ). Fixative osmic vapour 24 hours. Stained with methylene blue saturated in 80% alcohol. Mag. 1000 diams. Drawn when mounted in absolute; illumination of field varied, but mostly bright; very careful study with camera lucida of part of a cell.

Fig. 16. Pancreas. Frog. Fixative sublimate. Section 1 tooth (0.7 µ). (a) and (b) were in the same cell, (a) being almost continuous with (b). Mag. 2250 diams. Probably not made with camera lucida.

Fig. 17. Pancreas. Frog. Fixative sublimate. Section 1 tooth (± 0 7 µ). Drawing was not made with the camera lucida. Mag. 2250 diams.

Gut of Oniscus. Animals starved for 6 days.

Fig. 18. Fixative sublimate 2 hours; no exposure to water; dehydrated in alcohol with a trace of iodine. Section 2 teeth (1.4 µ). Stain, iron-haematoxylin. Camera lucida.

Fig. 19. Fixative osmic vapour 2 hours. Section 1 tooth (0.7 µ). Stain, iron-haematoxylin. Camera lucida.

Fig. 20. Oxyphil cell of red marrow. Fixative sublimate. Section between 2 and 3 focal planes thick. Illumination moderate. Mag. 2250 diams.

(a) freehand drawing of upper focal plane,

(b) freehand drawing of next deeper plane,

(c) combining these two planes and adding a third.' (209-210)

 

Fig. 1-3 in text:

'The effect of the concentration of the solution of the egg-white when it is above the minimum which is necessary for the production of a continuous mass in the fixed state is restricted to an alteration in the size of the meshes. Figures 1, 2 and 3 show the appearance of the net produced by sublimate in solutions of egg-white containing respectively 13, 30 and 60 grams solid per 100 c.c. The microscopical analysis of the figure in the last case is a very doubtful matter. When the microscope is pushed to these limits its powers are more potent in magnifying the personal equation of the observer than in really elucidating details of structure, seeing that the structures under observation become commensurate with the diffraction areas. However it is certain that there are discontinuities-the doubt is limited to whether the open net structure is still retained, or whether the spaces are discontinuous in the form of separate vesicles.' (171-172)

 

Fig. 1 in text:

'The following facts appeared to be established. 13% solution fixed with corrosive sublimate sections made after embedding in paraffin were found to show a sponge or net structure, the aspect of which is given in Figure 1. It proved to be impossible to stain any substance in the meshes of the net. They contained simple fluid, of which direct hand-pressure [note: 'That is, pressure applied by a glass rod to the substance when in a glass vessel.'] or a centrifugal machine expressed a quantity equal to ± 60% by volume of the entire gel.' (167)

 

Fig. 2 in text:

'The larger the grains and, up to certain limits, the fewer, the wider are the meshes and the thicker the bars. The grains of carmine commonly occurred in patches between which one had regions fairly free from solid particles. A study of such sections showed that when the grains were larger than the mesh in the grain-free parts of the colloid - that is to say the mesh formed in the absence of solid particles - the effect of a group of grains was to cause the mesh to widen out very much. If the grains are sufficiently numerous then each nodal point contains, or is formed, by one. If however they are too few and scattered the normal net is formed, but opens out here and there to lodge a single grain, or a group of grains on its nodal points (Fig. 2). So we may conclude that the grains modify the size of the meshes and the thickness of the bars by their number and their size. (186)

 

Fig. 5-8 intext:

'Gelatine. The figure in this case changes not only in dimensions but in character. If gelatine of medium concentration, say 7 to 15 grams solid to the 100 c.c. be fixed by alcohol, or sublimate, instead of forming an open net, it takes the form of a continuous solid hollowed out by vesicles about 7 µ in diameter (Fig. 6) which as a rule become deformed to polyhedra by mutual pressure. If it be fixed by formaline however an open net is produced; the formaline however must be in excess and be allowed to act on the gelatine for about 16 hours. The open net figure may be formed with alcohol or sublimate but in that case, supposing the reagent to be present in large excess, the percentage of gelatine in grams per 100 c.c. must be less than 5. The figure then consists of nodal spherules joined by bars as when white of egg is fixed (Fig. 5).

[table detailing dimensions of meshes and spaces here]

Figures 5 to 8 illustrate these cases. ' (172-173)

 

Figs. 9-10 in text:

'edge films do not owe their characters to drying since they are seen at the junction line of white of egg and olive oil when the former is coagulated, when the colloid solution is fixed while actually flowing over the surface, and also within the colloid mass itself in thin films which are formed between contiguous air-bubbles.

They may readily be made by dipping the corner of two coverslips held in the forceps into a solution of white of egg and at once fixing by momentary immersion in a steam jet. The preparation may then be examined in water, alcohol, or, after staining, in balsam. If the fixation was quickly done the colloid solution will have penetrated only a few millimetres from the corner; it was therefore fixed while still flowing. Figure 10 is a drawing of an edge film; it shows the abrupt transition from the non-staining to the staining portions. Figure 9 shows the optically structureless film at the junction of two air-bubbles.' (191)

 

Fig. 11 in text:

'The configuration of the cell-protoplasm was beautifully shown in these preparations. At the edge of the preparation exceedingly thin sections of cells were found from out of which the blue staining substance had fallen. One then had without doubt a honeycomb, the spaces of which did not appear to communicate with one another. (Fig. 11). The substance of the honeycomb portion of the cell was continuous with and in no sense different from the cell-protoplasm which formed the base and sides of the cell: clearly the honeycomb structure is simply the expression of the fact that the cell-protoplasm was hollowed out to hold the secretory granules: the spaces have been slightly enlarged by the partial swelling of the granules.' (195)

 

Fig. 12 in text:

'One can now see that the blue stained basal cell-protoplasm is continuous with the substance of a honeycomb in the polygonal spaces of which lie the granules. With a further fall in the percentage of alcohol the cell continues to expand in size to many times its original volume; the granules become less and less coloured until one sees only the blue stained cell-protoplasm, now expanded into exceedingly thin plates. If the percentage of alcohol has not fallen below 40, one can produce contraction of the cell by again raising the concentration of the alcohol until its volume is almost what it was at the beginning. The granules however do not recover the property of dyeing deeply with the methylene blue (Fig. 12). One can therefore stain the cell-protoplasm and so show that the spaces in the honeycomb agree in size with that of the granules before swelling occurred.' (196)

 

Figs. 13-15 in text:

'The configuration of the cell-substance when the granules were perfectly preserved was found to be that of a sponge-work of threads holding the granules on the nodal points. The form of the net varies according to whether the granules are very close set or not. In the former case the threads run simply from granule to granule, and iron-haematoxylin preparations of sections about 0.5 µ thick (less than one tooth) convey the impression that each granule is enclosed in a thin shell of cell-protoplasm from which bars run to the similar shell on neighbouring granules. Where the granules are less closely set the cell-protoplasm forms a net with nodal points of its own substance which stretches between the granules. A reference to the camera lucida drawings reproduced in Figs. 13, 14, and 15 will obviate further description.' (199)

 

Figs. 16-19 in text:

'Gland cells. When the granules neither swell nor dissolve, corrosive sublimate throws the cell-substance into an open net. The figure of the net depends upon the number and size of the granules. Figures 16a and 16b are from different regions of the same cell of the pancreas of a frog separated by only a short space. Figure 17 is from another cell.

The vapour of osmic acid produces a much finer structure. Where there are no granules the structure appears to be a fine honeycomb and not a net. Where granules occur the honeycomb opens out, the spaces becoming larger. Figures 18 and 19 representing the structure of the mesenteron cells of Oniscus after sublimate and osmic vapour respectively will illustrate this. The difference is partly due no doubt to the general shrinkage which accompanies fixation by osmic vapour.' (202-203)

 

Fig. 20 in text:

'in the thinnest sections one has a clear open mesh such as is shown in Fig. 20. As the sections increase in thickness one has more and more decidedly the impression that the net at any particular focal plane lies imbedded in a faint continuous grey ground substance. This impression is due to the haze from the focal planes above and below the one actually in focus. Figuires 20 a, b and c are from a cell in a section of medium thickness. The section of the cell was a little more than two visual fields in depth. Figure 20 a is a free-hand drawing of the upper visual field. Figure 20 b a similar drawing of the lower field. Figure 20 c is a drawing made with the camera lucida, the focal level being that of the upper visual field.' (205)