AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, DECEMBER 22 
THE PHYSIOLOGY OF ASCIDIA ATRA LESUEUR! 
II, SENSORY PHYSIOLOGY 
* SELIG HECHT 
TWO FIGURES 
CONTENTS 
I. The responses of Ascidia and their nervous relations................+. 261 
i Descriptions GMmreaCulOnss tari es sacs | > os Sereetverenenaterierie kara ake 2262 
DRAIN GIA KOU 1R5 MAO odd aoe dep tees pote Cacordtoon acco D.coNadoDeuO Code 266 
ie Mechanicalistimmulatianeys. i. crss.- os ohs < ci aiaistale« «'s~ ators ep tolaye os aieiehe! se earems 268 
Lge NOLiKelels oo odobte Hee Dao Be One cou Cat OUR nEEEnn es 4 Cao ono tnEoccen 268 
DPA VAT ose ia Vona\ee. ators conn Et, Ateneo Cine cRIETEEIEOG 6. CO.dOm non Sou mar 270 
GOPVEPEALeG SUIMULAETON +5 cs -t.c ses ae dhs cteysucl als acs + oo cudlotaly va dobehauerele) siete 273 
PD Tse ieee e A ese ees ake se bnad a 2. paietaetarerayeietete Os = Srailoel taney otarnomesieals 277 
IWS disor oA a ooo omeeere bid HOMO ae Hanae suo SCOrEncr Top tot OO codnac 279 
ilar TM avercnnoRancihnhighin anes cee ocea Ee deemc nous An6 eo mene one oume Cooma a 279 
PINATICey OLBEDSIDLVAb ys) oasis = sites cites Sane fel sie eee a elctereieto ea ac 281 
Wane hem iC alnstimil agin ys os <eteed ol «stars. sett met aaeumieke chats esleieister erat baron oerocte 283 
MBP resenceyor chemical: SGNse%,...:! 02-0 aval o-ale sow «is axe satebarenae sat 283 
DraINTE NOC OND orc kc ace Woes it ote alas al eee eaeeee cao eye Neh ave ao us ore Ses ereaaticks 284 
SUD IScrIDUbIGH Ol SCNSIULVELY. coc... 2 sett ee fete ia iecere )eleshacracyen.s 286 
ASE OST OLIC IPLESSULC se cote acts oie c a ovate 5 TER ROMO N te ore oils ay oh Ab cise oteha RN SLaet eb 287 
Da VesUitst wath Chemilea srr s,s 2 chi.n:5 + Acrea een + os cele nef nior-yonbsey are auerees © = 289 
Ge Natunevotathesenseorcansse nae era erotica 292 
WA SIN ina ane Become On Dont SoD BOR On Eia > obo cle Sonmee pone boocEUCac domes 296 
Wile. Bibliognap liye seasistec scree nae cera ec = cberckecelete setae hoa av ciotel sorsiete:» MA tetate 298 
I. THE RESPONSES OF ASCIDIA AND THEIR NERVOUS RELATIONS 
The assumption of a sessile mode of life involves a sacrifice 
in the number and kinds of responses of which an animal is 
capable. The comparatively few reactions exhibited by the 
sessile tunicates are undoubtedly accountable for the almost 
complete absence of our knowledge of their sensory physiology. 
The common European ascidian, Ciona intestinalis, is the only 
one in which anything is known of the behavior under stimulation. 
1 Contributions from the Bermuda Biological Station for Research, No. 79, 
and contributions from the Zodlogical Laboratory of the Museum of Compara- 
tive Zodlogy at Harvard College, No. 304. 
261 
