Description of figs. 1-6, Pl IV:

'Fig. 1. -Normal cornea of frog, stained with haematoxylin. Two of the branched corneal corpuscles are shown with a wandering cell, a, lying in the cell space with one of them. b b represent two of the wandering cells in the substance of the cornea; these have taken the elongated form.

Fig. 2. -Normal cornea of a cat, stained with silver and carmine. The ground substance is stained brown with the silver, leaving the cell spaces unstained. In these are seen the nuclei of the branched cells stained with carmine. b b, two wandering cells in the cell spaces.

Fig. 3. -Scleral edge of cat's cornea fourteen hours after central inflammation. The wandering cells, b b, are increased in number, and the communications between the spaces are larger than in No. 2. Silver and carmine.

Fig. 4. -Area of general infiltration forty hours after central inflammation. The cell spaces are greatly enlarged, and broken up into small areas by the brown silver lines. The ground substance is reduced in amount, in some places represented only as small islands.

Fig. 5. -Innermost limit of area of general infiltration. Here, as in No. 4, the cell spaces are greatly enlarged, and divided into small areas, in each of which the brightlystained horseshoe nucleus is seen. From this point to the centre no cellular elements are found. Silver and carmine.

Fig. 6. -Two corneal corpuseles, which have taken on regenerative changes. The nuclei have increased in number, and long processes which are much branched have grown out from the parent cell.' (87)

Fig. 1 in text:

'We... find, even in the normal cornea,... [a] set of cells, which cannot be considered a part of its fixed histological elements. Their numbers are variable; in some corneas very abundant, in others few: in animals of the same species sometimes they are found in greater numbers at one portion of the tissue, sometimes at another. In fresh preparations they can be seen to pass by active amoeboid movements from one place to another, and they never, so far as we can see, stand in any fixed histological relation to the other elements of the tissue; these are the "wandering cells." Their position is not at all constant; sometimes we find them lying in the cell space along with the branched corpuscles, sometimes in the narrow communication between two spaces, sometimes as long drawn out rods in the tissue between the fibres (b, Fig. 1, P1. IV.), sometimes in the nerve lymph channels, and in one preparation I have been so forttunate as to get one seemingly in the act of passing from the nerve channel into a cell space communicating with this, half of its body lying in the channel and half in the space.' (78-79)

Fig. 2 in text:

'Proceeding now to the cat's cornea, we meet here, even in the normal state, some difference from that of the frog. The corpuscles (Fig. 2), are smaller, are more numerous, and the cell spaces communicate by larger passages than in the frog. The brightly-staining wandering cells in the normal cornea are fewer in number than in the frog's cornea, and mostly found in the cell spaces.' (83)

Fig. 3 in text:

'Let us now see what the carmine staining shows in the two parts. In the outer ring we have (Fig. 3) in each of the slightly enlarged cell spaces the large oval nucleus of the branch cell totally unchanged, and staining in all respects like the normal.' (84)

Fig. 4 in text:

'The animal is first etherized and the cornea touched with the caustic... If we examine such a cornea, say 40 hours after cauterization, and as yet unstained by carmine, the changes found can be divided into two heads. Of these the first will comprise the changes around the outer corneal edge, and the second those in the immediate neighbourhood of the eschar... 

In the immediate neighbourhood of the eschar the change is more pronounced, and different from anything we have hitherto seen. These changes are all the more important to us, since it is here that Stricker says the corneal corpuscles are undergoing the most rapid proliferation. In the silver preparations we see, lying in the coloured ground, groups of small white spaces with dark brown lines separating them from one another (Fig. 4); these groups correspond in shape to enlarged cell spaces.' (83-84)

Fig. 5 in text:

'Proceeding now from the corneal edge towards the eschar, we come to a region where the corneal corpuscles are wanting... the corneal corpuscles are dead-have been destroyed by the caustic. The cell spaces can be seen, most of them much shrunken, but no nucleus in them, or anything which would afford us proof of the presence of a corneal corpuscle. Lying in these cell spaces, but still more in the tissue between them, are seen multitudes of cells before described, at the scleral edge. These cells become more numerous as we proceed, until we reach a territory where the cell spaces are filled with them (Fig. 5). The spaces here are enlarged, and the communications between neighbouring ones are wider; spaces and communications are all full, and no one comparing these cells with those at the outer (i.e., the scleral) edge can doubt for a moment that they are similar.' (85)

Fig. 6 in text:

'In the corneal corpuscles which form the line outside the zone of infiltration, and which indicate the separation of the dead from the living proper corneal tissue, we find changes as early as twenty hours after cauterisation... At a later period (30 to 40 hours) the nuclei can be seen in different stages of division, and at the same time long processes are sent out from the cells into the dead tissue. These processes become longer (Fig. 6), nuclei pass from the old cell up into them, and thus they form in the dead tissue new corneal corpuscles, but n ever pus. These processes and new cells stain in all respects like parent cell from which they originated, and the nuclei have the same shape as in the old cells, though they stain more brightly, and are more granular.' (86)