60 On Conjoined Epithelium. By 8. Martyn. 
newest text-book on minute anatomy is almost, if not quite, 
identical with the earliest sketch in Yirchow's ' Archiv.' 
It is, nevertheless, twelve years since these cells were first dis- 
covered and named by Professor Max Schultze ; and their distribu- 
tion in fishes and amphibia has been fully described (1867) by his 
brother, Professor Franz Schultze. They have been subsequently 
noticed by Kolliker, Frey, Eindfleisch, Strieker, Cornil and Eanvier, 
Kollett, and others. They have been called "spinous cells,^' 
"echinate cells," "cellules dentelees," "ribbed" and "spiny and 
furrowed " cells ; but no observer seems to have added any careful 
researches to the original description of Max Schultze, by whom 
the name was given to them of " prickle and ridge " cells. And 
yet there is. a certain beauty and interest attaching to these 
structures which seem to entitle them to more detailed notice; 
and while they offer problems in histogenesis of great interest to 
the anatomist and physiologist, they cannot but do so also in some 
degree to the pathologist. It is a good illustration of the old story 
of " eyes and no eyes," that a very remarkable structure, and not a 
difficult one either, in so thoroughly common a place as the borders 
of an epithelial cell, should have been persistently overlooked for 
many years, and long after high microscopic object-glasses had been 
brought to great perfection. No one need despair of seeing some- 
thing new and important by looking with extra carefulness at what 
is, so to speak, straight before his face, after this fact, that the mere 
form of the simplest of all animal cells actually remained unnoticed 
until a dozen years ago. 
The discovery of Max Schultze, then, was this : that in the 
epithelium of the mouth and conjunctiva firstly, and then in the 
epidermis of the skin, and indeed wherever there is true pavement 
or scaly epithelium in many layers, the second series upwards of 
cells have this pecuhar character. Their surface is furnished with 
short projections, which are apt to appear as prickles; while some- 
times there are ridges (reefs) marking portions of the cell with 
parallel groovings (see drawing). The lowest layer of epidermic 
cells consists of elongated vertical palisading-like elements, between 
and underneath which lie germinal masses of indeterminate form. 
Next above, and completing what was called " rete mucosum," is a 
succession of layers of spheroidal cells, becoming more and more 
flattened until they cohere under the form of mere scales into 
cuticle on the skin, or in a less firm manner in transitional situa- 
tions like the mouth, conjunctiva, &c. It is these latter layers 
which are mostly spinous. There is some difficulty in seeing this 
well in thick skin. It was already noticed by Max Schultze, that 
the diseases involving the true skin showed the prickle-cells weU ; 
and other observers, especially Cornil and lianvier, have followed in 
the same line (Fig. 1). 
