94 REPORTS OF inve;stigations and proje;cts. 



manner seed was obtained during the summer of 1908 from 3 latas arising as 

 mutants from pure-bred lamarckiana; these have produced respectively 73^ 

 35, and 18 offspring during the season of 1909. (The same method was em- 

 ployed to secure fertilization of No. 3378 F^ extracted lata derived from O. 

 lata 2X0. gigas $ , 1908, mentioned in the second paragraph of this report.) 

 One individual from each of the three families has been artificially self-polli- 

 nated, and it is hoped that seed will be obtained for a second generation. Of 

 equal interest is the cross between O. lamarckiana 2 and O. lata S (76 

 offspring) never before produced, so far as has been ascertained. The recip- 

 rocal cross (repeatedly grown at this station) was also included (45 offspring), 

 but, owing to limitations of space and time for study, all of these two lots 

 were discarded at the time of transplantation, except such mutants as were 

 recognized among them. 



All of the above-mentioned species, mutants, and hybrids have been the 

 subject of individual daily study since germination and, as mentioned for the 

 offspring of O. lamarckiana 2X0. gigas S , each has been carefully de- 

 scribed at regular intervals throughout its life-history; leaves, buds, and 

 flowers have been preserved for measurements, and (with the exception of a 

 few recorded in the summary appended) five or six fixations of root-tips for 

 chromosome study have been made from each of the above in early rosette 

 stages. 



The cross between O. lata 2 and O. gigas $ , studied in detail in 1908, was 

 repeated to determine whether the offspring of a second cross would behave 

 in general as did those of the previous season. 33 of the 71 plants under 

 observation during early rosette stages were transplanted to the garden in 

 May. No chromosome fixations were made. 



The majority of the offspring of O. lata 2X0. gigas $ having shown 

 themselves to be intermediate between the two parents, iDoth in respect to ex- 

 ternal vegetative characters and number of chromosomes, I became interested 

 in ascertaining whether two parents differing widely in number of chromo- 

 somes as do lata (15) and gigas (28—29 or 30) would not regularly produce 

 intermediate offspring ; also whether two parents having the same number of 

 chromosomes, or differing in point of i (as lata 15, lamarckiana 14) might not 

 produce, as a rule, only pure parental types among the offspring (exclusive of 

 mutants), as had been demonstrated to be the case with lata 2 X lamarck- 

 iana $ . With this in view the following cultures were grown : 



O. nanella 9x0. gigas (^ 90 offspring. 



O. lamarckiana 9x6. gigas (^ 52 oflFspring. 



O. nanella 9 X O. lamarckiana (^ . . 134 offspring. 



In addition to the above cultures i plant kept in sphagnum moss for two 

 years was brought to maturity as a perfectly normal healthy lamarckiana. 



Late in the summer young rosettes were found growing up from the roots 

 of flowering Fj offspring of O. lata 2X0. gigas $ ; one was removed from 

 hybrid No. 3380, 2 from No. 3750, 4 from No. 3385, and 6 from No. 3372. 

 These have been brought through the summer in excellent condition. An 

 opportunity was here presented to observe the effect of external conditions 

 upon the various cuttings taken from a single plant, with respect to bud- 

 coloration, branching habits, size of adult plant, date of maturity, etc. 



The following outline is added in conclusion to give a more concise idea of 

 the investigations carried on during the season of 1909. 



