REACTION OF EMBRYONIC CELLS TO SOLIDS 



535 



TABLE 3 

 Summary of results of experiments with cluck tissues 



CHARACTER OF CULTURE 



NLTHBER 

 OP PREP- 

 ARATIONS 



Plasma clot i 34 



Dejibr hutted serum 



Spider web 31 



Large drop 14 



Small drop 5 



Spread drop I 6 



Locke's solution 



Spider web 30 



Large drop 7 



Small drop 12 



Spread drop 3 



CELL WAN- 

 DERING ON 

 SOLID [ 



SUPPORT 



34 



23 



5 i 

 1 



19 



10 

 3 



CELLS ON 



SURFACE 



FILM 



PER CENT 



NO CELL POSITIVE 



WANDERING ON SOLID 



' SUPPORT 



100 



74 



100 

 17 



63 



83 



100 



8 

 13 



11 

 6 



1 



quently. It is of interest to note that in several of the large 

 drop preparations where the tissue was at first not in contact 

 with the cover, it afterwards did touch the glass and then cell 

 movement began. These have been classed with the small 

 drop (contact) group. 



The main results of these experiments can best be presented 

 by the description of four different cases taken from the same 

 series and shown in figures 8 to 11. The cultures are all from 

 pieces of the duodenum of a nine-day chick embryo, and the 

 drawings were made from specimens preserved two days after 

 preparation. 



The first (fig. 8) has been cultivated in clotted plasma. In 

 this there is a very characteristic ring formation with bands of 

 tissue extending across the clear space. Isolated mesenchyme 

 cells are present and the epithelium (endothelimn?) shows its 

 usual tendency to form membranes. 



The second (fig. 9) was cultivated in a small drop of defi- 

 brinated serum and the tissue was in contact with the cover- 

 slip from the beginning. The striking feature of this case is 

 the formation of a wide membrane extending out from nearly 

 the whole circumference of the original tissue. In one region 

 conditions have pre\'ented this movement, but at a distance from 



