CONDITION OF EPIDERMAL FIBRILS IN EPITHELIOMA. 289 
Organe und Gewebe iibernehmen die zuerst gleichartigen 
Zellen besondere Funktionen, die in besonderen Strukturen 
oder Differenzierungen iliren Ausdruck finden. 
“Alle diese Differenzierungen, so heterogen sie sind, 
enstehen nun durch Metamorphose eines und desselben 
elementareti Plasmabestandteiles, der Chondriosomen. Die 
Cliondriosomen sind das den Differenzierungsprozessen 
zugrunde liegende materielle Substrat, welches tC in den 
spezifisclien Substanzen der verschiedenen Gewebe different” 
wird. 
“Das Studium eines Teils diese Urnwaudlungen soil das 
Thema weiterer Arbeiten bilden : hier sei dariiber nur kurz 
folgendes bemerkt. 
“Zu den Differenzierungsprodukten der Chondriosomen 
gehoren zunachst einmal die verschiedensten Faserstrukturen : 
zahlreiche fibrillare Bildungen in Epithelzellen, z. B. nacli 
meinen demnachst zu beschreibenden Beobachtungen, die 
‘ Protoplasma - fasern 9 der Epideriniszellen, ferner die 
FibrilLm der glatten und quergestreiften Muskelfasern, die 
Neurofibrillen und Neurogliafasern, die Bindegewebsfasern.” 
It will be noticed that in the foregoing paragraph Meves 
expresses the belief that the“ protoplasmafasern” of epithelial 
cells, i.e. epidermal fibrils, are differentiation products of the 
choudriosomes. The observations which he was about to 
publish have not yet appeared in print, but in the meantime a 
paper has appeared from the pen of Jean Firket (1911) giving 
the results of his investigations on the fibrils and their 
relation to the chondriosomes in the epithelial cells of the 
embryo chick. 
At the time that the results of the observations embodied 
in this paper were being written, no evidence was obtainable 
that the epidermal fibrils arose from embryonic chondriosomes. 
That such was their origin must have seemed most probable 
to anyone who had given careful attention to the work of 
Meves, Duesberg aud Hoven on the origin of the connective- 
tissue, muscle and neurofibrils, and was, iudeed, cursorily 
indicated in the papers of the first two authors. 
