134 



HISTOLOGIC PROPERTIES AND REACTIONS. 



Iodine: 



C. lowianum, moderate, value 50. 



C. ebumeum, moderate, lighter than in C. lowianum, value 45. 



i eburn.-low., moderate, the same as in C. lowianum, value 50. 



m violet : 

 C. lowianum, moderate to moderately deep, value 55. 

 C. eburneum, light to moderately deep, slightly deeper than in 



lowianum, value 57. 

 C. eburn.-low., light to moderately deep, the same as in C. lowi- 

 anum, value 55. 

 Safranin: 



C. lowianum, moderate to moderately deep, value 52. 



C. eburneum, moderate to moderate'y deep, slightly deeper than 



in C. lowianum, value 55. 

 C. eburn.-low. , moderato to moderately deep, the same as in C. 

 lowianum, value 52. 

 Temperature: 



C. lowianum, in the majority at 58 to GO , in all at 62 to 03°, 

 mean 62.5°. 

 burneum, in the majority at 5S to 59.5°, in all at 65 to G6.5 , 

 mean 05.76°. 

 C. eburn.-low., in the majority at 61 to 63°, in all but rare grains at 

 67 to 68°, mean 67.5°. 



C. lowianum exhibits a higher reactivity than the 

 at in the polarization, iodine, and temperature 

 ions, and a lower reactivity in the gentian-violet and 

 safranin reactions. The hybrid has the same reactivities 

 as G. lowianum in the reactions with polarization, iodine, 

 gentian violet, and safranin, but has a lower reactivity 

 than cither parent with temperature, in which it is nearer 

 to 0. eburneum. 



Tahle A 1 I shows the reaction-intensities in percent- 

 ages of total starch gelatinized at definite intervals (sec- 

 and minutes). 



Velocity-reaction Curves. 



This section treats of the velocity-reaction curves of 



the starches of Cymbidium lowianum, C. eburneum, and 



( '. eburni o-lowianum 3 showing the quantitative difference 



in the behavior toward different reagents at definite tirne- 



<\ . (Chart I) 616 to D 618.) 



The reactions with the various reagents, with rare 

 exceptions, occur with such rapidity that such differences 

 as may have been noted are not conclusive, all three 

 starches being gelatinized completely or practically coni- 

 , within a minute or two, and often within 15 to 

 30 seconds. Where no differences are recorded between 

 the reactions of the parents those of the hybrid may be 

 distinctly different, as in the chloral-hydrate, pyrogallic- 

 acid, and barium-chloride reactions, especially in the 

 last. For the reason stated, only the curves of these 

 three reactions have been charted. 



Reaction i\n nsities of the Hybrid. 



This section treats of the reaction-intensities of the 

 hybrid as regards sameness, intermediateness, excess, and 

 deficit in relation to the parents. (Table A 11 and 

 Charts 1) 616 to !) 618.) 



The reactivities of the hybrid are the same as those 

 of the seed parenl in the reactions with polarization, 

 iodine, gentian viol ifranin ; the same as th 



the pollen parent in none; the same as those of both 

 parents with sulphuric acid, hydrochloric acid, pota - 

 sium hydroxide, potassium iodide, potassium Bulphocya- 

 . potassium sulphide, sodium hydroxide, sodium buI- 

 phidi . ntium nitrate, in all of which the reactions 



are too rapid for differentiation; intermediate or high- 

 est in none; and the lowest with temperature, chloral 

 hydrate, chromic acid, lie acid, nitric acid, so- 



dium salicylate, calcium nitrate, cobalt nitrate, copper 

 nitrate, cupric chloride, barium chloride, and mercuric 

 chloride (in 1 being closer to the pollen parent, and in 

 L2 as close to one as to the other parent). 



The following is a summary of the reaction-intensi- 

 ties: Same as seed parent, 4; same as pollen parent, 0; 



