IRIS. 



113 



(5) In /. sindjarensis the very high reactions with 

 pyrogallic acid, nitric acid, sulphuric acid, hydrochloric 

 acid, potassium hydroxide, potassium iodide, pota 

 sulphocyanate, sodium hydroxide, sodium sulphide, and 



cupric chloride; the high read - with polari 



chromic and. sodium salicylate, calcium mi rat'', uranium 

 nitrate, strontium nitrate, copper nitrate, and mercuric 

 chloride; the moderate reactions with iodine, gentian 

 violet, .-a I'ran in, and temperature ; the lo^ reactions with 

 cobalt nitrate and barium chloride reactions ; and thi , 

 low reactions with chloral hydrate and pota 

 sulphide. 



(6) In the hybrid the verj high reactions with pyro- 

 gallic arid, nitric arid, sulphuric acid, hydrochlorii 

 potassium hydroxide, potassium iodide, potassium sul- 

 phocyanate, sodium hydroxide, and sodium sulphide : the 

 high reactions with polarization, chromic acid, sodium 

 salicylate, calcium nitrate, uranium nitrate, strontium 

 nitrate, copper nitrate, cupric chloride, and mercuric 

 chloride] the moderate reactions with iodine, gentian 

 violet, safranin, and temperature; and the very low reac- 

 tions with chloral hydrate, potassium sulphide, cobalt 

 nitrate, and barium chloride. 



Following is a summary of the reaction-intensities: 



Verj 



low. 



I. persica v:ir. purpurea. 

 I- sindjarensis 



I. pursind. 



Notes on the Irises. 



Among the very striking features of the four charts 

 are : 



The closeness of all three curves in each chart and 

 the wavering relationship of the hybrid curve to one 

 or the other or both parental curves, occasionally going 

 alio-,,, or below parental extremes in Charts E 30, E 31, 

 and E :;::. and frequently (l"> out of 26 reactions) in 

 Chart E32; the close correspondence of tin- curvi 

 the three sets of rhizomatous irids (Charts E 30, E 31, 

 and E32); and the very definite differentiation of the 

 curves of the rhizomatous and tuberous sen,-. 



In the first set the cross is between members of the 

 subgenera Ococyclus and Apagon; in 1 econd set, 

 between members of the subgenera Ococyclus and Togo 

 niris and Regeliaj in the third set, between members ol 

 the subgenus Pogoniris and Regelia; and in the t urth 

 set. between members of the subgenus Juno. In the 

 three sets of rhizomatous irids the curves are so nearly 

 alike as to suggest that the subgeneric division oJ 

 selbring referred to in Part II is botanically largely 

 artificial, and that the primary division into rhizomatous 

 and tuberous groups is well founded in expressing funda 

 mental botanical differentiation. All lj one set 



of tuberous irises was studied in detail in this research, 

 cursory investigations were made with other memb 



es (including /. histrio Reichb., /. 

 1'., iss and Knit.. /. reticulata M. Bieb.. /. alata Poir., and 

 /. caucasica Hoffm. ; the first three be! 



is Xiphion and the last two to the subgenus ■hum), 



in all of which the reactions were in close correspondence 



with those of this set. In the previous research with 



irid starches it was found that the members of the rhizo- 



8 



matous series have in com the tuber- 



besides different histologic properl ii 

 de-ice of polarization, lower reactivities with iodine, 

 higher reactivitii with gentian violet and safranin, and 

 distinctly higher tempera gelatinization. Owing 



to improper strengths of the rcagenl 



led that is sa ntiate th 



then studied : I was clear e\ 



of the two serii -, the mi 1 the rhizi 



a whole, highi r 1 ■ with chloral hy- 



drate and chi 



chloride and Purdy's solution. These results ari 

 : 1, c, i-,| »iili those of the present research, there being in 

 the rhizomatous series mean lower reactivities with pola- 

 rization and iodine, higher reactivities with gentian 

 violet and safranin, higher temperatui tinization, 



higher reactivity with chloral hydrate, 1 

 tendency to a higher reactivity with 1 hromic acid, and a 

 lower reactivity with potassium hydroxide. 



The types of curves of the rhi: 

 irids. respectively, differ chiefly in the relative lov 

 of the rhizomatous curve in the reactions with pyrogallic 

 acid, nitric acid, hyd acid, potassium hydro 



potassium iodide, -odium hydroxide, sodium sul : 

 calcium nitrate, uranium in!' ite, co >per nitrate, cupric 

 chloride, and mercuric chloride, and the highness in those 

 with chloral hydrate and -odium salicylate. Probably 



a 11 ion:; tic irids «ill be found some sj ies or hybrid that 



will, as in ea-e ,,| the crinums, bridge the two -eric-. 



Owing to the almost invariable closeness of the three 

 curves in each set, opportunity is rarely afforded for a 

 satisfactory study of the relation-hip- of the hyhr 

 one or the other or both parents. It will he si - 

 following summary, the figures of wl i I 1 he taken 



as having only tentative value-, that the different hy- 

 brids vary in their parental relationships, lly in 

 their intermediate, highest, and 1 rds. 



The following is a summary of the reaction-intensi- 

 ties of the hybrids a - sameness, intermediateness, 

 and deficit in n la I ion to t he pa rent - : 



The diffi n nces in the reactivi if the rhi- 



zomatous and tuberous series are indicated in the fol- 

 lowing table : 



Rhizomatous series: 

 1 il erica-trojana-ismali 

 1 . il erica -cengialti-dorak . - . 

 I. cengialti-pallida-mrs. grej 



Tuberous scries: 



1 persica sindjarensis-pursind 



Mod- 

 erate. 



g 



Low. 



B.9 B 

 9.7 



4 0.7 



Very 

 low. 



4.7 

 5 



5.7 



3.1 



