92 REPORTS OF INVESTIGATIONS AND PROJECTS. 



a view to arranging transplantation experiments. About 500 offspring are 

 now being reared from the living material brought back, and some material 

 was also collected for the purpose of studying geographic variation. It is 

 hoped that the living material secured on this trip will breed in the green- 

 house here during the winter, when the native crickets are hibernating. Dr. 

 Lutz plans next summer to pay especial attention to the effect of humidity 

 upon the wing dimorphism. 



EVOLUTION IN THE COCCINEELID.^. 



This work, which has been continued by Mr. Roswell Hill Johnson, is now 

 drawing to a close, owing to his impending departure from the Station. Re- 

 ports on the results attained are being prepared. His major paper deals with 

 determinate evolution in the color-pattern of lady-beetles. He has also writ- 

 ten several papers of more general import, the outcome of reflections and ob- 

 servations on these insects. 



BREEDING STRAINS OF PLANTS. 



Dr. George H. Shull, although occupied during much of the year (from 

 February 15 to May 30) with his study of Mr. Burbank's horticultural meth- 

 ods and results, has been able to continue most of the strains listed in last 

 year's report. He concluded his work on Bursa past oris and has presented 

 an important paper on the subject for publication. This species shows its 

 composite nature in a fashion as to make it hardly less interesting than the 

 evening-primrose. On August 14 he started on a tour of the principal plant- 

 breeding establishments of Europe. 



In hybrid beans it has been demonstrated that a mottled seed-coat, which 

 appears as a novelty in several crosses, becomes evident only when in the 

 heterozygous state. Individuals which possess the mottling factor in the 

 homozygous condition are indistinguishable from those which lack this factor 

 altogether. The mottled character which appears as a novelty in these crosses 

 can not be segregated as a permanent characteristic of a pure strain, but 

 plants possessing this character, when self-fertilized, continue to give only 50 

 per cent of mottled offspring. They form in respect to mottling a mid-race. 

 The peculiar behavior of the mottling in these beans has given rise to the 

 ratio 18:18:6:6:16, which has not been reported hitherto. The fact that 

 the pure-bred dominants with respect to mottling are not mottled, even when 

 pigment is present, makes it impossible to determine at this time whether the 

 mottled pattern was derived from the pigmented bean or the white one, though 

 it was assumed at first that it came from the latter. Means are now at hand 

 for the solution of this problem, but the necessity of leaving the cultures on 

 August 14, before the beans had begun to bloom, has made it necessary to 

 postpone this matter until another season. Two other cases of latency have 

 also been demonstrated in these beans. Both the White Flageolet and the 



