9-i s. IKEXO : 



its flowering begins in Jnne and continues till tlie end of October. Flowers 

 are Tieautiful and pretty large ; they begin generally to open at about 8 

 o'clock morning under sausliiue, and wither at about the noon of the same 

 day, though in duU weather or in late summer it may CDutinue to open much 

 longer. Each flower is provided ■vWth two sepals and five to sis petals ; there 

 are very numerous slender filaments derived h'orn five stamens by copious 

 ramification ; there is one ovary with one style and five to six radiating 

 stigmas, wliich ripans into a pyxis containing a large number of tiny Mdney- 

 shapad seeds. In respect to the colour of the petals there are, so far as I 

 know, five different kinds : they are, namely, white, yellow, orange, flesh- 

 colom-ed, red, and magenta (s. PI II), natm-ally with some fluctuations in 

 their tone. Petals striped in varioiis waj-s are also foimd. It may here be 

 remarked that the flower-colour of PoHulaca is always due to the cell-sap, 

 and never to the chromoplasts. 



Materials and Methods. 



The lireeding experiments of several colour-varieties of tliis plant were 

 begun in 1915 to studj' the genetical behaviom- of flower-colours. Fii-st of 

 all, I have done the self-fertilisation of varieties cultivated in our Botanical 

 Garden in Komaba as well as those obtained from other sources, including 

 white, yeUow, orange, red and magenta. Next year seeds got by such selfiug 

 were sown. Some of the vaiieties thus examined were foimd to S3gi-egate, 

 proving themselves to be hybrids ; all such ones were rejected, and only 

 those which were found to breed true to their respective t3'pe3 were further 

 cultivated, seeds being taken of course every generation on selfed flowers.' 



From 1915 I have begun to cross these varieties in various ways, 

 and are now concerned in shid3Üng the behaviom- of their ofispriug. Many 

 of these crosses were repeated, and also their oflspring were also studied. 

 A variety which bears flesh-colom-ed flowei-s was got fii'st in 1917 thi-ough 

 the kindness of Dr. I. Nagai in the Agiicultural Experiment Station in 

 Oomagari near Akita ; its hybridisation with some other colour-varieties was 

 made in 1918, so that we liad in 1920 their i^^-offepring. 



' (to nccoiiiit of ijoor gcrminntion of seeds I bnve lost the red imrcnt in 1917 and tlie 

 ■white-I one in 1!)18, but I ha\e rccovcrcil each of them afterwanls by extracting tliem from their 

 respective hybrids male sjme years ago, anl continue to ciülivate them till now. 



