414 



SCIENCE 



[N. S. Vol. XXXIV. No. 87* 



' ' The Spermatogenesis of an Hemipteron, Eu- 

 scbistus, ' ' Thos. H. Montgomery, Jr. 



' ' The Life History of the Scolex polymorphus 

 of the Woods Hole Region, ' ' Winterton 'C. Curtis. 



SPECIAL ASTICLES 



ON SOME CONDITIONS OF TISSUE GROWTH, ESPE- 

 CULLY IN CULTURE MEDIA 



In a paper on the regeneration of epithelium 

 published almost fourteen years ago^ I an- 

 alyzed some of the internal and external fac- 

 tors in the growth of mammalian tissues and 

 demonstrated the existence of stereotropism in 

 regenerating epithelial cells. I also cited cer- 

 tain statements of other observers which sug- 

 gested to me the existence of a stereotropic 

 sensitiveness in other varieties of growing 

 vertebrate tissues. 



At that time I furthermore had the oppor- 

 tunity to observe that epithelium might grow 

 and show its stereotropic reaction without 

 relation to the underlying tissue, growing 

 merely in contact with blood coagula. This 

 observation suggested to me the possibility of 

 cultivating tissues of vertebrates in culture 

 media in vivo as well as in vitro, in a similar 

 manner as bacteria had been cultivated. My 

 previous observations on the importance of the 

 contact with solid substances in tissue growth 

 induced me to use solid coagula as the culture 

 medium." I published a communication con- 

 cerning these first experiments (which had 

 been carried out in Baltimore).' In further 

 experiments accidental conditions made it 

 necessary to study the growth of mammalian 

 tissues in culture media with the animal body 

 acting as an incubator. The results of these 

 experiments have been published in detail.* 

 To our knowledge in these earlier experiments, 

 for the first time the attempt was recorded in 



^"Ueber Eegeneration des Epithels" (chapter 

 13), Arcliiv f. Entiv'mech., Bd. VI., 1898. 



'1 referred to this circumstance again in a 

 communication to the Society of Experimental 

 Biology and Medicine, Proceedings of the 44th 

 meeting, May 17, 1911. 



''Chicago, 1907. 



* ArcTiiv f. Entw'mech., Bd. XIII., 1902; Journ, 

 Med. Research, Vol. VIII., 1902; Jouni. Am. Med. 

 Association, 1901. 



the literature to grow tissues of higher ani- 

 mals under artificial conditions, to separate 

 through culture media experimentally grow- 

 ing epithelial from connective tissue cells and 

 furthermore to study the infiuence of the ad- 

 dition of certain chemicals upon the growth 

 of tissues." 



Demands of other investigations- prevented 

 me from extending these experiments inta 

 various directions, as I had planned to do for 

 a considerable number of years. Only re- 

 cently I resumed these studies and I analyzed 

 further the growth of tissues in solid coagula, 

 especially differentiating between the reac- 

 tions of stroma and parenchyma in tissue 

 growth in culture media. Here I will add the- 

 resiilts of some further studies which were 

 made in conjunction with my collaborator,. 

 Dr. Moyer S. Fleisher, and a more detailed 

 account of which will appear elsewhere. 



1. We investigated to what extent oxygen is- 

 necessary for the growth of mammalian tis- 

 sues in culture media, a problem which had 

 interested me from the beginning of my ex- 

 periments. In the case of certain higher 

 plants it has been recently shown that a lim- 

 ited anaerobic growth is possible. We used 

 various methods of anaerobic culture methods 

 and we also studied the effect of a diminution 

 in the supply of oxygen. Our results show 

 that growth ceases if oxygen is lacking or 

 noticeably diminished. This applies to various- 

 tissues. A noteworthy difference in the reac- 

 tion of various tissues to lack of oxygen we 

 could not observe. Under these conditions 

 tissues not only cease to grow, but they die. 

 It is much more difficult to determine the 

 effect of an increase in the tension of oxygen 

 on tissue growth. Our experiments, however, 

 make it very probable that in certain cases 

 the life and growth of tissues is favorably in- 

 fiueneed if pure oxygen takes the place of air- 

 surrounding the culture media. 



2. We studied the effect of the combined 

 growth of an oidium-like organism" and of 



° Zeitschrift f. Erehsforschung, Bd. V., 1907. 



" This organism was studied in conjunction with 

 Dr. George J. Moore, of St. Louis, and will be 

 described elsewhere. 



