82 



seem lo Ih' llic cMsc. I-; I) (• I i II ^' "" has invesli<fnle(l Ihe 

 influcnc." <•! (littcicr.l osmotic picssiii-cs on llie i^rowth of 

 t'iln-ol)l;isls ;iii(l round tluil (lcci-c;is,' and increase in osniolic 

 picssni't- I'esnlled in a lower ^rowlli rale .\|)|)arenlly llic 

 widlh ol llu' area of new cells <^ro\\ n in a hypotonic cnl- 

 Inri' medinni was lar^ei\ hul (liinnei-. so Ihal (he aclual 

 amount ol' new lissue was less. 



I'Or (|nik' sonic time it was staled l)y (', a i' r e I '■' Ihal 

 when cuilnres were kept under conditions in wiiich Iwo 

 phases allernated. a phasi- ol aclive lite in a |)lasmatic me- 

 dium in Ihe incubator, and a piiasc ol' lalcid life in H i ji- 

 gers solulion in Ihe rel'rigeralor, they could easily he 

 kepi alive. 



The Ihonghl was this, thai during the lalenl period of 

 life all the calabolic substances could be removed and then 

 be rejuvinated for the aclive period of life in the culture 

 medium But it was observed shortly after that a much 

 more uniform growth could he obtained by a sim])le and 

 bricl" washing in Ringer's solulion and afterwards being 

 transferred to a fresh medium. 



The technical paiM of the culture work, as it according 

 to Carrel is carried out today, shall be described. 



PREPARATION OF THE CULTURE MEDIA. 



1. Prei^aralion of the Plasma. The animal of 

 which llu plasma is to be taken is usually starved for a day 

 or so previous lo llie blood being taken. P\)r tlie cultivation 

 of chicken tissues, the plasma is taken from adult chickens. 

 The best plasma is obtained from young, healthy adult 

 chickens not over two years old. If the chickens are not 

 starved twenty-four hours before bleeding, the plasma ob- 

 tained is turbid and rich in fat globules. Such plasma 

 gives ail unclear clot in which the cells do not develop as 

 well as in tlie clear |)lasma. Under ether narcosis the blood 

 vessel, arlerv oi" vein, usually one of the carolids. is dissected 



