10 



BULLETIN &71, U. S. DEPARTMElsTT OF AGRICULTUEE. 



Table IV. — Comparison of the staminate and pistillate inflorescences of the 

 fourth generation of the Ramosa-Gordo maize hybrid Mhl58. 





Measurements of tassel length (centimeters). 



Number of branches. 



Central 

 spike 

 index. 



Parental des- 

 ignation. 



Entire 



Branch- 

 ing 

 space. 



Central 

 spike. 



Upper- 

 most 

 branch. 



Lowest 

 branch. 



Tassel. 



Ear. 



L2L1L1 



L2L1L2 



L2L1L3 



L2L1L4 



L2L1L5 



L2L1L6 



L2L1L7 



L2L1L8 



1,2L1L9 



L2L1L11 



1,2L1L12 



L2L2L1 



L2L2L2 



L2L2L3 



L2L2L4 



L2L2L5 



L2L2L6 



37. 6± 0.64 

 41. 6± 0.79 

 41.1 ±0.80 

 34. 3± 0.58 

 35. 5± 0.60 

 41. 4± 0.72 

 31. 5± 0.71 

 37. 5± 0.52 

 32. 5± 0.55 

 35. 2± 0.62 

 37. 9 ±0.69 

 40. 8± 0.67 

 32. 7± 1.10 

 33.0 ±0.92 

 31. 0± 0.63 

 29.4±0.75 

 26.7±0.89 



20. 2± 0.41 

 20. 7 ±0.56 

 24.7±0.63 

 15.8±0.58 

 21.9±0.31 

 17. 5± 0.66 

 22.2±0.53 

 25. 3 ±0.47 

 21. 5± 0.45 

 19. 6 ±0.53 

 22. 2± 0.74 

 15.7±0.69 

 17. 7± 0.72 

 22. 4± 0.68 

 17. 9± 0.49 

 15. 5± 0.37 

 12. 5± 1.04 



17. 4± 0.59 

 20. 8± 0.87 

 16. 1± 0.66 

 18. 7 ±0.51 

 13. 5± 0.53 

 23. 9± 0.66 

 9.2±0.41 

 12. 0± 0.50 

 11.0±0.42 

 15.6±0.44 

 15.6±0.69 

 25.1 ±1.13 

 14. 6± 1.12 

 10. 4± 0.63 

 13. 0± 0.68 

 13.9±0.53 

 14.2±0.S0 



4.6±0.18 

 6.9±0.53 

 5.3±0.21 

 5.1±0.28 

 4.4±0.26 

 8.4±0.55 

 3.2±0.69 

 4.1±0.20 

 4.0±0.19 

 5.8±0.33 

 5.4±0.28 

 13. 4± 0.88 

 5.2±0.37 

 5.5±0.41 

 4.2±0.14 

 4.5±0.24 

 4.5±0.29 



26. 3± 0.60 

 23. 6± 0.64 

 25. 8± 0.63 

 21. 5± 0.52 

 17. 3 ±0.58 

 28. 2 ±0.58 

 16.8±0.64 

 21.0±0.61 

 16. 0± 0.50 

 17. 6± 1.44 

 23. 8 ±0.65 

 24.2±0.93 

 14. 4± 0.58 

 18. 5± 0.35 

 18. 0± 0.60 

 16. 8± 0.42 

 13. 4± 0.53 



43. 4± 1.27 

 23.2±1.5 

 48.4±2.1 

 23. 0± 1.35 

 41. 2± 1.12 

 22. 2± 1.46 

 48. 3± 1.66 

 54. 2± 1.90 

 41. 7± 1.47 

 39. 2± 1.32 

 36. 0± 1.70 

 32. 2± 1.67 

 30. 2± 1.53 

 52. 3± 1.93 

 50.4±2.13 

 25. 2± 1. 06 

 22. 3 ±2. 16 



3.5±0.62 

 



5.5±0.65 

 

 .3 

 



14.1±5.84 

 9.5±1.05 

 4.5±0.87 

 7.9±1.19 

 2.3±0.62 



'"3.'9±6.'89 

 11. 2± 1.06 



""'.'6 



3.6 



45. 6± 1.14 

 49.6±1.9 

 39. 0± 1.18 

 54. 7± 1.36 

 37. 6± 0.97 

 57. 8± 1.43 

 29. 2± 1.37 

 32. 0± 1.16 

 33. 7± 1.06 

 44. 4± 1.13 

 41.1 ±1.68 

 60.0±2.12 

 43. 9± 1.48 

 30. 9± 1.51 

 41. 3± 1.40 

 47. 0± 1.26 

 53.6±2.53 



The distribution of the Fg, Fg, and the F^ plants for branches on 

 the ear is shown in Table V, and the distribution for the branches on 

 the tassel in Table VI. The number of branches on the ear is the best 

 single quantitative expression for the degree of branching, although 

 subject to a certain variation due to variation in the size of the whole 

 inflorescence. 



In Table VI the positions of the parent plants are shown by plus 

 marks. The positions of plants which bore ramose ears are shown 

 by italic figures ; where there were two such plants only one of them 

 bore a ramose ear except in a single instance (marked with a star at 

 line 54, column 38) wherein two plants bore ramose ears. 



In the tassels of the F^ the difficulty of giving a single expression 

 for the degree of branching is much greater. This may be due to 

 the larger size of the staminate inflorescence, which tends to empha- 

 size the variability by magnifying small differences. The total num- 

 ber of tassel branches is, of course, reduced on plants of low vigor, 

 and in a general way this may be reflected in a reduction in the size 

 of the entire inflorescence, though the correlation between the size of 

 the tassel and the number of branches in the ramose segregates of the 

 F2 is but 0.123 ±0.066. The best indication of the ramose character 

 is the general form of the inflorescence, which is difficult to reduce 

 to a single expression. Thus, in one F^ progeny many of the plants 

 developed in addition to the usual basal branches one or two branches 

 midway in what otherwise was a normal central spike (PI. XII). 

 In some of these plants also the pedicels of the paired spikelets grad- 

 ually increased in length toward the base of the central spike, giving 

 this organ a pronounced conical shape (PI. XI). Neither the num- 



