SUMMARIES OF THE HISTOLOGIC CHARACTERS, BT( 



305 



pollen parent ; in Iris three incline to the .-ced parent 

 and one to the pollen parent ; and in Ccdanthe one in- 

 clines to the s I parent ami one to the pollen parent. 



In the quantitative reactions this absence <>( con I 

 to one or the other parent is much more marked; thus, 

 m only Brunsdonna and Begonia do all of these chloral- 

 hydrate reactions tend to the seed parent; hut in no 

 genus do al! of them incline to the pollen parent. Exam- 

 ining the differenl generic groups we not.' thai in Hip- 

 peastrum in two hybrids the reactions incline to the seed 

 parent and in one to the pollen parent ; in Hamanthus 

 in one hybrid the reaction incline- to one as much as to 

 the other parent, and in the other to the seed parent ; 

 in Crinum one inclines to the ^<-'\ parent and two to the 

 pollen parent; in Nerine one inclines to the seed parent 

 and four to the pollen parent ; in Narcissus five incline 

 to the seed parent, six to the pollen parent, and two in- 

 cline to one as much as to the other parent; in I. ilium two 

 incline to the seed parent and three to the pollen parent; 

 in Iris two incline to one as much as to the other parent, 

 and two incline to the pollen parent; and in Caianthe 

 one inclines to the seed parent and the other inclines to 

 one as much as to the other parent. Of exceptional 

 interest is the fact, several times noted, that in case of 

 any hybrid the qualitative and quantitative reactions 

 may or may not correspond in their parental inclinations. 

 It. is certainly remarkable that with a given reagent the 

 qualitative reaction may correspond with that of the seed 

 parent and the quantitative reaction with that of the 

 pollen parent, or vice versa, and so on in other varied 

 relationships. 



The tendency in general to a ratio of approximately 

 2: 1 in the qualitative reactions in their relations to the 

 seed and pollen parents is well marked. This ratio 

 varies from 4 : to 1:1, hut in about half of the cases it 

 will be found to be as first stated. Totaling these rec- 

 ords, it will be seen that 62.8 per cent of these reactions 

 incline to the seed parent and 33.8 per cent to the pollen 

 parent, a ratio of 1.8:1. In other words, there is 

 approximately twice the tendency for the qualitative 

 reaction to be closer to the seed parent than to the pollen 

 parent. 



There is not a corresponding tendency to such a com- 

 mon ratio in the quantitative reactions, but to a marked 

 inconstancy. In the qualitative reactions the ratio is 

 always in favor of the seed parent; hut in the quantita- 

 tive reactions it may be in favor of either or of neither 

 parent. Thus, it is found that there may be a ratio 

 of 4 : 1 in favor of the seed parent, or one of 1 : 3 or 1 : t 

 in favor of the pollen parent, and intermediate grada- 

 tions. Summing up these reactions, ■! I per cent incline 

 to the seed parent and 40 per cent to the pollen parent— 

 a ratio of approximately 1:1. In studying the quanti- 

 tative records the large number of reactions that are 

 recorded as being the same as those of both parents 

 should be taken into consideration, because had these 

 been shown to have had in each case, or even in nest 

 cases, definite uniparental inclinations these ratios would 

 of course be subject to more or less modification. Nearly 

 all these reactions showed no difference from the pare] tal 

 reactions because of gelatinization occurring with too 

 great a rapidity or slowness for differentiation. Minn- 

 tied strengths of reagents would doubtless have elicited 

 differences that arc wholly obscured by very quick or 

 20 



slow reai tions. It is, b ible that there 



would be brought about any important chai 

 h hole, hi i hi e ra( ios. \\ hy the qualitative ra' 



ii the quantitative ral 

 problematical, very inti re ting, and \ 



tereochemic pei uliai it e of tl 



No feature of thi ds is more remarkable than 



the n ' i al of the qua 

 of a given starch with a their parental 



ioliii.it ions. It is of importam i 



Qomenon is not peculiar to any starch or n mt is 



common, and doubt I mon to all to all 



reagents. With qoI a single starch wa-s it found that 

 there was not such reversal; and with only four of the 

 reagents (stronl urn nitrate, barium i and mer- 



curic chloride | was reversal not rec u for 



which is doubtless to be found in the small numb 

 qualitative reaction,- recorded with thi u\< (four 



reactions with the with thi and four 



with the third). Not less remarkable than the rev 

 of the reactions is the frequency with which I 

 nomenon occur-, the pe m 6 in the 



iodine reactions to as high as 50 in th balt-nitrati 



cupric-chloride reactions with the different starches. The 

 mean is 22.5, or close to one-fourth. 



Table E. 



♦ Qualitative reactions = polarization ficure; quantitative 

 = polarization intensity. 



