756 H. E. KNow.tTon 
ranging from 17° to 21° C., in darkness. Altho there were some exceptions, | 
the duration of life was longest at 30 per cent humidity or in a perfectly | 
dry atmosphere. Some of his data are given in table 1: 
TABLE 1. Some or THE REsutts oF PrunpT’s INVESTIGATIONS OF THE EFFECT oF Mots- 
TURE ON PoLLEN LONGEVITY 
Per cent of moisture Over 
Species Se SO. 
90 60 30 
Aesculus hippocastanum................-.- 6 days 17 days 72 days 72 days — 
INEST USI NAD Oss ono auc Goede podcesoanee 1 1 I 1 
TEES (HRTOTR 8 os os os Wa a awe Bia Hoe be 32 46 59 53 
Ampelopsis quinquefolia...............--. 6 11 23 19 
Alguilegiawl gan Sre srr ee ys eee ce 5 14 84 92 
Glematisintegnifoliaaen janice. eecieeeee 6 24 89 103 
COnNUS MOSH Ace OR ee 31 59 74 59 
Corylus Avellanaef 303 cc cohen ie. Sie | cane nae | -stocbeeye Se ee 65 
ID NPIS SONI NURI So Ga olson ciao Shades deeds 9 13 43 172 
EAD PUTS VUULG OTS ieee = tate era eye 5 5 3-5 2 
MOEN SUS ULLON Uae tere ete eer tee ae 13 3 29 23 
TVA UL eRUNie tien ace eee eee ie 8 31 142 142 
Miclilotustalvusesmrcn erate.) eer eee 6 14 96 73 
Mer cunialisspenennissmeac ricci tee a cer 8-10 | 29 58 72 
Oenotherasviennise see eee ee 2 6 8 6 
BONO CMUSHULCOLUS HE Eee cee eer 11 30 92 92 
IRODOUCTARYOGACALT se er center ea er re 33 17 49 49 
Pinus: Montang.o.. ceie.ek ie oe otk heel ie 2)|) GR See eo eee 272 
IPUNUs SYWESITIS Rs 6 a Od og Sie ols ie eI Gono tasl| lela Oe |e ee 279 
PUTUSMGLUS sak od Ses Ok Se eee EE Orne ee eee 70 
IRlontagOMNedi Greener ee 3 12 50 68 
POOKCOMDTCSSO ne ee ae eee een 1 1 1 1 
iRolentillatangenteaence eee aa eee ee 2 5 21 44 
Prunus, COnASUSIACIEG: @ i .- 82) sie. nein es all oe eee ||) eee a |e 81 
IPTUNUS | DEOUS INS EN GREE Sette an et eee: 14 22 181 181 
Salixialba Maite aisha dees Se Neen || a mele eee a th eae a 57 
SGINGIGTOCUIS eevee sa Ga Se A ini eS Scene 12 18 38 52 
ISECOLESCET COLE ani mee eine mein Mie in pan. 12 hours | 12 hours | 12 hours 12 hours | 
SOLUTUMN CULCOINONG a nee aac eer 7 days 9 days 41 days 41 days | 
ET OOSCONO MV AURGUIULC Os en ee teehee yr eee 2 3 31 40 
Malina Gesneniang ase ee ee ete 23 43 108 92 
Gliustcammestiisa ae or er oe ee 6 9 22 17 
VAabUr num OPUlas fects excise) Soroe ae eset e «Gers s)|| Vo ce ajb2-0 2 5i|| See ee 164 
Witness baocsoocouss or DN ain, fr eee ne trl ie Peer MORRIS || co oy 0.05.6 21 
Weal OUb Gis Gace do cooodnaoge oscatodsoe 19 28 217 235 
—— 
Crandall (1913), storing pollen in covered petri dishes, found that | 
apple pollen one month old would not germinate, but that when eleven | 
days old it was still capable of fertilization. Strawberry pollen three | 
