loi 

 i 



,..U-(I lissiif ;m(l llic cover ,<j;l;iss. which serves its support 

 . .• Ihi- inij^ralioii ol' Hie cells. I iisiwilly |)lace the slides 

 .11 llie iiiciibnlor upside down: in oilier words the euUure; 

 chainher resis on the eo\cr -i;lass in llie incnhalor. The tissues 

 will llu'ii he al Hie holloin. i e towards the cover f^lass 

 and a j^ood i-oiilacl hetweeii the tissue and the support is 

 established If this precaulioii is not taken, the tissue frag- 

 ment will in most cases be found floating in the hulk of 

 Hie drop and the cells are not able to inigi'ale. 



Ihe teclini({ue of m i c ro m an i ]) u 1 a t i o n which has 

 been applied to the tissue cultivation sliould be mentioned 

 here. 



\'arious substances can be inoeidaled into thi' cultui'ei 

 medium during the observation of the living tissue cells 

 in the incubator. Brans-'*; has used this technique a 

 good deal and by means of the finest Speemanns need- 

 les lie was able to cut growing cell elements. 



By means of the B a )• b e i* s i", "; micro-dissection iech- 

 nique or still better with that l)y Chambers "" modified. 

 Barber technique, it is even possible to inoculate various 

 substances into the cytoplasm of a living tissue cell. It is 

 also possible to introduce living bacilli into the protoplasm 

 of the tissue cells. By the Chambers i-'*, i-i) method 

 parts of the body of the living tissue cell can be excised; 

 the nucleus may be cut in two or single chromosomes may 

 be removed. 



P'or obtaining good p h o t og r a p h s of tissue cultures, Ihe 

 Lewis and Lewis cultures give excellent results because 

 the cells are in one single layer, namely on the cover glass, 

 and because everything but the tissue cells can be removed 

 from the cover glass. 



It is more difficult to obtain good microgrammes from 

 tissue; cultivated in plasma media. Here we often get the 

 plasma coagulum tinted al the same time as the cells 



