64 



The summer of 1938 was s]K'nt in field-work in Tennessee and 

 adjoinins^" slates, lart^e eolleetions heint^- made on the Cuml)erlan(l 

 Plateau and in the oak l)arrens ot' Middle 'I'cnnessee, chielly in 

 Coffee and l^'ranklin Counties, ddie eolleetion of material for oiu' 

 herl)arium (al)()Ut 8000 specimens) will ser\-e as tlie l)asis (in ad- 

 dition to ])revious worl\ ) tor an annotated discussion ot the ])lants 

 ot Teiniessee, an area now un(k'r<^"()ing' extensive ehan<4"es owini^^ to 

 the huildini^- of t.^'reat dams in the valley of the Tennessee Rixer 

 1))' the Teiniessee X'alk'v Authority (the so-called T. V. A.) of the 

 Federal CJoxernment. In addition to herhaidum material assem- 

 hled for jiermanent records a lart^e numher of ])hoto<4raphs were 

 taken in natural color. For hel]) durni^^ this held work I ha\'C 

 been es])eciahy indehted to Dr. W. AI. Jennison, of the University 

 of Tennessee and Botanist for the Great .Sm(jky Mountains Na- 

 tional Park; to Dr. j. Al . Shaver, ol l'eal)o(h- College, an authority 

 on the ^■egetation of the Xash\-ille area; and to Dr. Roland AI. 

 Harper, of the State Ceolo^ical Surx'ey of Alahama. 



In addition to routine work, I am en^^aj^ed in a sur\ev of the 

 vegetation ot the ^■allev ot the Ikitavia Kill in the northern Cat- 

 skill Ah)imtains ; in identification ol sedi^'es 1 rom temperate and 

 tropical America; and in tlie ])reparation of a flora of Cocos Island. 



GENiiTICS 



llxpcrunoilaJ J^innlion in NrpliroJcpis 

 By P.\r,pii C. BEM:n]CT 



The Ah'plirolcpis collections ha\'e keen maintained, hoth as a 

 record of research carried on and ])uhlishe(l here at the (jarden, 

 and as a hasis for fin'ther research. Ivirly in kkkS, Dr. A. ¥. 

 Blakeslee sui^t^estecl the institution of exi)eriinental work on ferns 

 with colchicine. Dr. l)lakeslee and associates at Cold Sprint.^" 

 llarhor ha\-e heen ohtainini^' some si,s.;inlR"uit results with this 

 chemical cju lloweriny ])lants, liverworts, and other g-roui)S of 

 ])lants. 



The use of colchicine as a means of artificially indncino' varia- 

 tion in i)lants has oi)ene(l up a very ])ronhsin!4- line of investis^ation 

 which holds considerahle ])ossihilities of ])ractical \alue as well as 

 scientifk: interest. This chemical has heen shown to ha\-e the 



