152 Agkioultural Experiment Station, Ithaca, N. Y. 



was less marked. The first heads to develop were noticed on Snowball 

 plants, March 21st, near the end of the bed farthest from the light. 

 The first heads, were sold March 29th, from near the dark end of the 

 house. The harvest was continued until May 1st, as demand arose, the 

 largest heads being taken at each gathering. On the first day of May, 

 all the remaining heads were picked. The table (page 132) gives 

 the yield and measurements of the plants, proceeding from the light 

 end to the dark end of the bed. There were five rows running length- 

 wise the bed, Nos. 1, 3 and 5 being Dwarf Erfurt and Nos. 2 and 4 

 Early Snowball. The plants were set about 16 inches apart, so that 

 there were forty-one rows crosswise the bed, each row containing five 

 plants, three of Erfurt and two of Snowball. The table shows the 

 behavior of each variety in reference to proximity to the light, earli- 

 ness, weight of entire plant without root, diameter of head when 

 picked, and length of the longest leaf. The plants which were 

 harvested on May 1st, when the experiment had closed, are not 

 included in these figures. 



Heview. — While it is true that the very earliest heads were obtained 

 from points far removed from the light, there does not appear to be 

 any uniform behavior, so far as these measurements go, in reference to 

 the light. Plants near the light wei'e much injured, and it is only 

 until the fifth or sixth rows are reached — or a distance of seven to ten 

 feet — that plants and heads of normal size are procured. It must be 

 said, however, that the lamp hung so low that beyond fifteen or twenty 

 feet the plants were much shaded by their own leaves and by plants in 

 front of them, and that the influence of the rays was therefore much 

 broken. The general results, therefore, seem to indicate that tlie bane- 

 ful influence of the naked electric arc lamp, of this pattern, is dissipated, 

 in cauliflowers, at a distance of about ten feet, and that beyond that 

 point the light appears to exert little influence. 



3. Experiments with Color Screens . 



It would be useful to know what parts of the spectrum produce the 

 singular effects which we have observed in our experiments. The good 

 results which follow the use of a clear glass screen indicate that some 

 of the injury is wrought by the ultra-violet rays. It is supposed, however, 

 that the orange rays promote assimilation and consequently may accel- 

 erate growth. Two yearsa go an experiment was projected to determine 

 the behavior of [)lants under electric lights of different colors. A lamp 

 like the one used for the other experiments was surrounded by a six-sided 

 frame, the back of which was a bright tin reflector to throw the light 



