PLATE 1 



Photographs of the stained preparations 



EXPLANATION OF FIGURES 



2 Mesenchyme cells growing from a neural tube after 48 hours of cultivation 

 in oxalated plasma. Stain, haematoxylin and Congo-red. X175. 



3 A layer of mesenchyme cells growing in a very thin clot. Fibrin has disap- 

 peared throughout the cellular layer. Eight-day culture. Held's molybdic acid 

 haematoxylin stain. X125. 



