The Microscope. 195 



all observers, on the contrary, who were convinced of the absence 

 of lymph-channels proper, these being filled almost entirely with 

 branching protoplasmic tracts, the migration appeared as an 

 almost inexplicable phenomenon. The possibility could, however 

 be admitted that the creeping bodies find their way between the 

 lamelke of the cornea, which were connected by filaments travers- 

 ing interstices of a certain width, although the presence of such 

 interstices could not be proved in traverse sections through the 

 cornea, stained either with chloride of gold, or nitrate of silver, 



S. Strieker, professor of general patholog}^ at the University 

 in Vienna, in 1880 first made a startling statement as to the inti- 

 mate nature of the " migratory cells." He denies the existence 

 of lymph spaces in the cornea, since he takes the ground that 

 all spaces are filled with protoplasm. He corroborates my as- 

 sertion that in the living cornea both the cornea corpuscles and 

 the basis substance are alive, that protoplasm may, at any mo- 

 ment, be transformed into basis substance, and the latter into 

 protoplasm. He argues in the following way : Since there are 

 but extremely narrow interstices between the cornea-corpuscles 

 and the basis substance, there is no possibility of the migration 

 •of protoplasmic lumps, just as little as there is a possibility of 

 moving a pea between the skin and a tightly fitting glove. 

 Strieker claims that the whole doctrine of " migratory cells " in 

 the cornea is a mistake. What von Recklinghausen described 

 as amoeboid and moving cells, were neither amcieboid nor moving, 

 but merely pieces of protoplasm which appear in the basis sub- 

 stance at one point owing to a liquefaction of the latter. This 

 basis substance being dissolved in a succession of points, and re- 

 established in an opposite direction, the appearance of locomo- 

 tion is conveyed to the observer. Strieker compares this process 

 to a piece of wax spread out upon a plate, under which an alco- 

 hol lamp is slowly moved. Where the heat is most intense, the 

 wax melts, whereas the cooled off" portions soon become hard 

 again. 



When I read these assertions, I confess I felt much sur- 

 prised, although they were in harmony with my own views, 

 which I had held ever since 1874. All doubts, however, vanished 

 from my mind when Strieker showed me the so-called migratory 

 corpuscles of slightly inflamed corneas of frogs, during my so- 

 journ in Vienna in 1883. Neither do these bodies push forward 



