| OCR Text |
Show CALIFORNICA. CIL\P. IV. ESOHSOHOLTZIA 116 of uito equal lengths, and three long rows, b ow ever ' wdeerde snoo tt hat qi t woul d b a ve bl een ex-e much crow ' h many capsu os were the plantds.ffiw~:lt to have ascertained o':llin (g to undertake so tremcly I ·f 1 bad been WI 1 B t db them, even 1 t all the capsu es. u produce y k to collect and coun . t ·n tho green-laborious a tas as 1 nts grown In po s I this was feasible with the p :ere much less fertile than those bouse. and although th.ese lative fertility appeared, ftfter care-. . ' ut of doors, tbeu re Tbe nineteen plants of growmg o to be the same. tl , 210 fully observing them, . ·n the pots produced al:oge 1er .- the English-crossed stock J 1 t (calculated as nineteen) pro-sules. the intercrossed p anb s ·noteen self-fertilised plants, cap ' 1 . and t e n1 t · d ·n duced 137.22 capsu es' . the number of seeds con a me .J 152 capsules. Now, knowi~~ it is easy to calculate the reh:ttivc. forty-five capsules of each d ob, n,n equal number of tho plants of numbers of seeds produce y the three lots. 1 nun1bor of naturally-Numb er of Seeds producecl by an OCJ.Ua fertilised plants. Sretls. d and self-fertilised Plants of English-crosse . as 100 to 40 parentage · ·. h ·. d and intorcrosscd Plants of tbe Enghs -crosse . . . . n,s 100 to 4:5 parentage· · · d and ~elf-fertilised Plants of the intercrosse (; " • as 100 to 89 parentage · · · · d 1 ts . of the intorcrossc p an The superiority in productiv:~~:on the grandchildren of. t~1C (that is, the prodn~t of a ~ross . the self-fortilisocl, sinall ~sIt J.s' plants which grew m Brazil) over mber of seed. contamccl m is wholly due to the lar~er avera~:;lu lants produced fewer capthe capsules; for tbe lntercro~ th~ self-fertilised pbnts. Tb~ sules in the greenhouse thar: did f the English-cros.·cd over great superiority in produc.tivenoss nob tho larger number o,f the self-fertilised pl9,nts lS show y mbor of contained , c~cls, capsules produced, the larger avoragec~~"ules As the Enghs~- d the smaller number of empty P· ff. ·ng of crosses m acnro ssed and jntercrosse d p 1a nt s wore the bo -osnp nth e case from tl1 e every previous generation (a~ Inust haven ewe may conclude that flowers being sterile wit? theu ow~ polle ) 'f the English-crossed the great superiority In prod.ncbven~~s t~e two parents of the over the intercrossed plants. lS dt~e d'fferent conditions. former having been long subJected o 1 CHAP. IV. RESEDA LUTEA. 117 The English-crossed plants, though so superior in productiveness, were, as we have seen, decidedly inferior in height and weight to the self-fertilised, and only equal to, or hardly superior to, the intercrossed plants. Therefore, the whole advantage of a cross with a distinct stock is here confined to productiveness, and I have met with no ~imilar case. VIII. RESEDA.CEiE.-RESEDA I,U'fEA . Seeds collected from wild plants growing in this neighbourhood were sown in the kitchen- garden ; and sev6ral of the seedlings thus raised W("l'e covered with a net. Of these, some were found (as will hereafter be more fully described) to be absolutely sterile when left to fertilise themselves spontaneously, although plenty of pollen fell on their stigmas ; and they were equally sterile when artificially and repeatedly ftrtilised with their own pollen; whil~t other plants produced a few spontaneously self-fertilised capsules. The remaining plants were left uncovered, and as pollen was oorried from plant to plant by the hive and humble-bees which incessantly visit the :flowers, they produced an abundance of capsules. Of the necessity of pollen being carried from one plant to another, I had ample evidence in the case of this species and of R. odorata; for those plants, which set no seeds or very f(jw as long as they were protected from insects, became loaded with capsules immediately that they were uncovered. Seeds from the flowers spontaneously self-fertilised under the net, and from flowers naturally crossed by the bees, were sown on opposite sides of five large pots. The seedlings were thinned as soon as they appeared above ground, so that an equal number were left on the two sides. After a time the pots were plunged into the open ground. The same number of plants of crossed and self-fertilised parentage were measured up to the summits of their flower-stems, with the result given in the following table (XXXV.). Those which did not produce flower-stems were not measured. The average height of the twenty-four crossed plants is here 17·17 inches, and that of the same number of self-fertilised phnts 14·61; or as 100 to 85. Of the crossed plants all but five flowered, whilst several of the self-fertilised did not do so. The above pairs, whilst still jn flower, but with some capsules already formed, were afterwards cut down and weighed. The crossed |
