196 



My c\|)i'i-imc-iils of conti-ollcd ^i-owili wcri' made on 

 llie small inU'sliiic I'l-oin chickiii cmhryos which were al)()ul 

 l(» lialch, i. o. 20 U) 21 days ohi. The |)iir|)Osc' ol' Ihe cx- 

 periiiicnls was lo sec if il was j)()ssil)h' lo oblain portions 

 of inleslinal lissue which, by means of liieir e|)illiciial lining, 

 were able lo resorb nulrimenl from Ihe suri-oundiiiifs and 

 supply Ihc entire fraifinent with nourishmeiil. Therefore 

 the intestine of the old embryo was seleeled in order to get 

 an epilhchum which had developed the ability of !)reaking 

 down foreign proteins and trans])orliiig Ihe substances to Ihe 

 interior of the tissue. 



techxioup:. 



20 to 21 days old chicken embryos were taken out oi Ihe 

 shell in the usually way. A fragment of the small intestine 

 was extirpated and placed in H ingers solution, llei'e il was 

 cut into very tiny fragments and i)laced in the culture 

 medium consisting of equal volumes of chicken plasma and 

 embryonic tissue juice. In some experiments the intestine 

 was opened and a little strip was cut off and cultivated, 

 or the fragment of intestine was turned inside out. leaving 

 the epithelial coat outside and the serosa inside the lumen. 



After 48 hours incubation the cultures were unsealed 

 and the small fragment picked up with the point of the 

 knife, or aspirated by means of a pipette, waslied a minute 

 or so in Ringer solution and re])laced in a fresh cidture 

 medium. An extensive liquefaction was brought about after 

 the 18 hours cultivation so the fragment was usually found 

 floating in a cup-like excavation in the liquefied plasma, 



RESULTS. 



It was very seldom observed, that the cells were growing 

 out in the medium, as explants generalW do manifest their 

 ac-tual life. Aftei" a few passages Ihe e|)illielium could \)c 

 seen growing all around the fragment and formed an entire 

 coat. At this stage, the fragment had become spherical and 



