832 



EXPEEIMENT STATION- EECOED. 



The composition of yellow alfalfa at various stages of development was found 

 to be as follows : 



Composition of yellow alfalfa at various stages of groioih. 



Consideration of the parents and the hybrids showed that an upright growth 

 was made by M. sativa and a rather trailing growth by the yellow alfalfa, 

 while the hybrids were intermediate in this character; the hybrids were also 

 intermediate between the parents in thickness of growth and height. The 

 yellow alfalfa bloomed most uniformly. In the coloring and the width of the 

 leaves and the drooping attitude of the leaves, the hybrid plants ranged be- 

 tween the parents. In abundance of foliage the hybrids approached the yellow 

 alfalfa, while in shape and coloring of the seed the hybrid ranged between the 

 parents. 



A special type of cage for the isolation of tlie flower stalk of mother 

 beets, O. Munebati {Atti R. Accad. Lined, Rend. CI. Sci. Fis., Mat. e Nat. 5. 

 ser., 23 (1914), II, No. 12, pp. 616-620, figs. 3). — This describes a cage consisting 

 of a square-framed top covered with wire netting to which is attached a muslin 

 curtain that surrounds the stalk and is secured around it at its base. The 

 whole is supported by two sticks driven into the ground on opposite sides of 

 the plant. It is noted that this type of cage effectively prevents cross-pollina- 

 tion, yet admits air and light and allows of easy access to the flower stalk for 

 hand-pollination or examination. 



Bed clover seed production: Pollination studies, J. M. Westgate and H. S. 

 CoE {U. S. Dept. Agr. Bui. 289 (1915), pp. 31, figs. 7).— This bulletin briefly 

 reviews the work of previous investigators and describes the structure, develop- 

 ment, and fertilization of red clover flowers as well as the experimental meth- 

 ods employed by the authors in securing cross-pollination and self-pollination 

 at Ames, Iowa (in collaboration with H. D. Hughes, L. H. Pammell, and 

 J. N. Martin), Lafayette, Ind. (in collaboration with A. T. Wiancko and F. E. 

 Robbins), and Arlington, Va. 



In regard to potency of pollen in self-pollination it is noted that " an exami- 

 nation of 30 flowers which had been self-pollinated for 55 hours showed good 

 germination on the stigmas, but no fertilization. The number of pollen grains 

 germinating on the stigmas ranged from 3 to 25 in each of the 30 flowers. 

 The tubes had made a slow growth and none exceeded 4 mm. in length. An 

 examination of 20 flowers which had been self-pollinated for 90 hours showed 

 that one pollen tube had attained a length of 7.5 mm., while the others were 

 5 mm. or less in length. At this rate of growth the longest tube would have 

 required about 48 hours more to reach the ovules, or about six days to traverse 

 tlie entire distance from stigma to ovule. Flowers examined four days after 

 springing the carinas showed the eggs in a disintegrated condition. It is there- 

 fore probable that in case of self-pollination the pollen tubes do not reach the 

 ovules In time to effect fertilization. An examination of the 30 flowers which 



