PHAIUS MILTONIA. 



131 



highest with polarization, gentian violet, and safranin, 

 in all closer to the seed parent; and lowest with chloral 

 hydrate, potassium sulphide, and sodium hydroxide (in 

 2 being closer to the pollen parent, and in 1 as close to one 

 as to the other parent) . 



The following is a summary of the reaction-intensi- 

 ties : Same as seed parent, 1 ; same as pollen parent 3 

 same as both parents, 5; intermediate, 11; highest' 3'- 

 lowest, 3. 



In these reactions the parents seem to share about 

 equally their influences in determining the characters 

 of the starch of the hybrid. The tendency to inter- 

 mediateness is quite marked, and in about one-half of 

 these reactions there is mid-intermediateness. There is a 

 stronger tendency to highest or lowest reactivity than to 

 sameness to one or the other parent. 



COMPOSITE CURVES OF THE REACTION-INTENSITIES. 

 This section treats of the composite curves of the 

 reaction-intensities, showing the differentiation of the 

 starches of Phaius grandifolius, P. wallichii and P hn- 

 bridus. ( Chart E 42.) 



Among the most conspicuous features of this chart 

 are: 



The very close correspondence in the rises and falls 

 of the curves and in most of the reactions the closeness 

 of the curves to one another, suggesting closely related 

 members of the same genus. The curve of Phaiiis 

 grandifolnis is higher than the curve of the other 

 parent P. wallichii in the reactions with polarization 

 iodine, gentian violet, safranin, chloral hydrate and 

 sodium hydroxide; lower with temperature, chromic 

 acid, pyrogallic acid, potassium iodide, sodium sali- 

 cylate, calcium nitrate, uranium nitrate, cobalt nitrate, 

 cupric chloride, barium chloride, and mercuric chloride ; 

 and the same or practically the same with nitric acid' 

 sulphuric acid, hydrochloric acid, potassium hydroxide, 

 potassium sulphocyanate, potassium sulphide, sodium sul- 

 phide, strontium nitrate, and copper nitrate. In P 

 grandifolius the very high reactions with polarization 

 nitric acid, sulphuric acid, hydrochloric acid, potassium 

 hydroxide, potassium sulphocyanate, potassium sulphide 

 sodium hydroxide, sodium sulphide, calcium nitrate' 

 strontium nitrate, and copper nitrate; the high with 

 safranin, chromic acid, potassium iodide, sodium sali- 

 cylate, uranium nitrate; the moderate with iodine 

 gentian violet, temperature, cupric chloride, and mer- 

 curic chloride; the low with chloral hydrate, pyro- 

 gallic acid, and cobalt nitrate; and the very low with 

 barium chloride. In P. wallichii the very high reactions 

 with polarization, chromic acid, nitric 'acid, sulphuric 

 acid, hydrochloric acid, potassium hydroxide, potassium 

 iodide, potassium sulphocyanate, potassium sulphide, 

 sodium hydroxide, sodium sulphide, sodium salicylate 

 calcium nitrate, uranium nitrate, strontium nitrate, cop- 

 per nitrate, and cupric chloride; the high with safra- 

 nin and mercuric chloride; the moderate with io- 

 dine, gentian violet, temperature, pyrogallic acid, and 

 cobalt nitrate; the low with chloral hydrate; and the 

 very low with barium chloride. In P. hybridus the 

 very high reactions with polarization, nitric acid, hydro- 

 chloric acid, potassium hydroxide, potassium sulpho- 

 cyanate, potassium sulphide, sodium hydroxide, sodium 

 sulphide, sodium salicylate, calcium nitrate, uranium 

 nitrate, strontium nitrate, and copper nitrate; the hi-h 

 with gentian violet, safranin, chromic acid, potassium 

 iodide,- cupric chloride, and mercuric chloride ; the mod- 

 erate with iodine and temperature ; the low with chloral 

 hydrate, pyrogallic acid, and cobalt nitrate; and the very 

 low with barium chloride. 



43. COMPARISONS OF THE STAECHES OF MILTONIA 



VEXILLABIA, M. ECEZLII, AND M. BLEUANA. 



In the histologic characteristics, polariscopic figures, 

 reactions with selenite, qualitative reactions with iodine' 

 and qualitative reactions with the various chemical rea- 

 gents, all three starches exhibit properties in common 

 m varying degrees of development together with individ- 

 ualities, the sum of which in each case is characteristic 

 ot the starch. The starch of Miltonia rcczlii in compari- 

 son with that of M. vexillaria shows less numerous com- 

 pound grains; more varied aggregates and a larger 

 number of the mosaic type; irregularities more frequent 

 and more pronounced (there are differences in the fre- 

 quency of the appearance of given forms of irregularity) 

 a somewhat abrupt flattening at the distal margin may 

 be observed, which peculiarity is not seen in the other 

 starch ; flattening is more frequent in grains with second- 

 ary lamella?. The hilum is somewhat more frequently 

 fissured, and when not fissured is less distinct- quite 

 refractive hila rare; cavity directed longitudinally and 

 cletts more frequent; fissure projected from the hilum 

 generally deeper, more frequently branched and more 

 common; eccentricity less. The lamella are less often 

 demonstrable, and there are a number of variations in 

 their distribution and grouping. The size is larger with 

 a marked tendency to broadness. In the polariscopic 

 selenite, and qualitative iodine reactions there are many 

 inferences. In the qualitative reactions with chloral 

 hydrate, chromic acid, hydrochloric acid, potassium io- 

 dide, and sodium salicylate there are many similarities 

 and dissimilarities, some of the latter being quite marked 

 The starch of the hybrid in comparison with the starches 

 the parents contains larger numbers of compound 

 rrams and aggregates; irregularities are slightly less 

 than in M. vexillaria and considerably less than 'in M 

 razlu; a lateral extension of secondary lamella is less 

 frequently seen than in M. rcezJii. The hilum when fis- 

 sured is more distinct and is more frequently refractive 

 than in either parent and there are various modifications 

 m the characters of the fissures and clefts ; eccentricity 

 is about the same as in M. rcczln and less than in M. vexit- 

 lana. The size is larger than in either parent The 

 hybrid starch is in form, character of the hilum, and char- 

 acters of the lamellae more closelv related to M vexil- 

 laria; but in eccentricity of the hilum and size it is closer 

 to M. rce.zlu. In the polariscopic, selenite, and qualita- 

 tive iodine reactions there are obvious leanings to ore 

 or the other parent, but the relationship is on the whole 

 distinctly closer to M. vexillaria. In the qualitative 

 chemical reactions, while the relationships are on the 

 whole distinctly closer to M. vexillaria, the influences of 

 M. rcezlu on the hybrid starch are markedly manifest. 

 Reaction-intensities Expressed ly Liglit, Color, and Tempera- 

 ture Reactions. 

 Polarization: 



M. vexillaria, high to very high, value 85. 

 M. razlii, moderate to very high, lower than in M. vexillaria 



value 75. 

 M. bleuana, high to very high, higher than in either parent 



value 88. 

 iodine: 



M. vexillaria, moderate, value 55. 



M. roezlii, moderate, lighter than in M. vexillaria, value 50 

 M. bleuana, moderate, the same as in M. vexillaria, value 55. 



