200 



only a I'ainl Iracc of llu' slroina rcinaint'd. V\(^. II. .liisl 

 under \\\v lininjf i'i)illuliiiin. which Mijpcarcd In he noi-inal. 

 were a largi- niinilx-i- oT cijitliclial cells in a niorc or less 

 ameboid slaU'. Inder this layer, an emply s|)ac(' conld 

 he seen which had prohahly been tilled with litiuid. and 

 liiinllv toward the centre of the body, a very thin, loose 

 sironii with sinj^lc connective tissue cells 



The cylindrical epithelium was very well pi'eserved. Its 

 frei' surface formed a continuous and solid ciilicula. 'This 

 conlracl between the epithelial cells was only perfecl in 

 Ibeir peripberal part. Between the external and the basal 

 l)arts of the cells, free spaces could be seen, as if they had 

 been formed by the pressure of a licpiid within the body. 

 (Fig. -15). 



The conditions under which the intestinal bodies lived 

 in a liquid medium were probably not the very best. The 

 correct conditions of life in a fluid medium will doubtlessly 

 be found and perhaps it will render possible maintaining 

 the life of these for a long time. And it will be interesting 

 to observe whether they are able to utilize heterologous 

 nutriment because otherwise the epilhelinm of the intestine 

 is capable of breaking down com[)lex foodstuffs. 



Interactions of the differenl cell elements can be studied 

 on these intestinal bodies. Transplantations have already 

 been undertaken. Pure cultures of epithelium were grafted 

 into such an "organism" without difficulty. The growth of 

 malignant cells may be sludii'd in the same way; the incii)ienl 

 growth of malignant cells in an organism can easil}' be 

 studied this way. 



Before closing this chapter, some very important results 

 obtained h\ Carrel and Ebeling within very recent 

 limes, should be reported here. As the results of a long 

 series of investigations on the physiology of the leucocytes, 

 Carrel and Ebeling •^^) ^^^) have quite recently shown 

 that the leucocytes actually secrete substances w^hich serve 

 as nutrition for other cells. 



