304 
ANNALES DE L’INSTITUT PASTEUR 
The testis ivas used , and with this tissue the virus usually 
grows as well as with the cornea. The virus was inoeulated in 
the testis of a guinea-pig. Five days later the animal was 
killed and the emulsified testis inoeulated on the shaven 
skin of a rabhit, but with négative resuit, the virus having 
been killed in vivo (1). 
The following experiments proved that living tissue was 
necessary to the growth of the virus in these préparations. In 
préparations in which killed cornea was used in place of the 
living tissue no growth of the virus occurred ; the living tissue 
control préparations showed active multiplication. The cor- 
neal tissue was killed by freezing or by a weak hypotonie sait 
solution, as these two methods cause very slight Chemical 
changes. The results obtained are in harmony with Ilie 
general conception of the close association of the virus with 
living bod) cells. 
Microscopie Studies. — Many préparations were studied his- 
tologically using several methods of fixation and staining. 
Examinations were also made on fresh unstained préparations 
with light and dark field illumination.* The results of these 
studies may he given in a few words. The corneal epithelium 
shows an active latéral spreading through the clôt, forming 
sheets or groups of cells in the plasma. The cells early show 
an accumulation of fat in their cytoplasm, but may retain their 
form for several weeks even when not transferred to fresh 
plasma. Gareful studies hâve failed to reveal any spécifie 
vaccine bodies in the préparations : only the smaller, undiffe- 
rentiated forms hâve been scen and these hâve been found in 
both the Controls without the virus and the virus préparations 
after incubation. Although we hâve observed numerous gra¬ 
nules in the incubated préparations, these hâve not been suffi- 
ciently definite in character with the methods employed thus far 
to permit us, as yet, to make any statement in regard to them. 
In the préparations containing pièces of testis the growth 
consisted largely of spindle-shaped connective tissue cells, 
with an occasional wandering out of round cells. The picture 
(1) See addendum. 
