Purser — On Inflammation and Suppuration. 159 
The wandering cells discovered, and so named by Von Reckling- 
hausen, were shown by him to exist in the healthy cornea in varyicg 
numbers. They perfectly resemble white blood or pus cells, and are 
found in all the connective tissues except cartilage. They possess 
power of spontaneous locomotion, and are hence called wandering, to 
distinguish them from the immoveable or fixed cells of the tissues. 
The idea that these wandering cells multiply by division, and so give 
origin to the corpuscles of pus is rejected by Cohnheim. He thinks that 
the irregular distribution of the wandering cells makes it very unlikely 
that they could by their proliferation produce the equable distribution 
of pus observed in keratitis, and he dwells on the fact that no one had 
ever seen a leucocyte divide, and that the supposed multiplication of 
pus cells by division was absolutely unsupported by direct observation. 
This, which was quite true when Cohnheim wrote, is so no longer. 
Strieker*' has seen pus corpuscles divide in the tongue of the frog, and 
in the cornea of the same animal. Kleinf has observed the same 
phenomenon in human white blood corpuscles and in those of the frog 
and triton, and I have seen it myself in the blood of the frog. 
The second way of accounting for the pus cells in the cornea is by 
supposing that they do not originate in the cornea itself^ but that they 
wander into it from without. That this is possible is proved by a 
beautiful experiment of Y. Recklinghausen. A freshly excised cornea 
is placed under the skin of a living frog in one of the large subcutaneous 
lymphatic spaces, which in this animal separate the skin from the 
subjacent parts. At the end of some hours it is removed and examined, 
and is found to contain great numbers of moveable corpuscles, re- 
sembling in every particular those of lymph or pus. Besides these the 
stellate connective tissue cells are present in their ordinary form. The 
moveable corpuscles have therefore not originated in the cornea itself, 
but have crept into it from without, a fact which is still further proved 
by their being found at an early period of the experiment only at the 
edges of the preparation . 
Cohnheim states that, as in the case just described, so after injury 
to the central part of the cornea in a living animal, the pus corpuscles 
get into the cornea from the edge. He describes how, after central 
cauterisation, the grey opacity, due to the presence of pus, commences to 
appear at the periphery of the cornea and gradually reaches the seat of 
injury, concentrating itself finally about this, while the peripheral 
parts become again clear. With the microscope the process can be 
followed by examining different corneae at different periods after the 
infliction of the injury. At first the pus is seen only at the margin, 
and mostly at those parts which correspond to the insertion of the recti 
muscles, while the portion of cornea between this and the central eschar 
is unaltered. Then the region occupied by the pus extends towards 
* Loc. cit. s. 18 et seq. 
t Henle and Meissner. Bericht, &:c. 1869, s. 14. 
