778 



DATA OF PROPERTIES OF STARCHES OF PARENT- AND HYBRID-STOCKS. 



cent of the entire number of grains and 89 per cent of 

 the total starch in 3 minutes ; in about 94 per cent of the 

 grains and 97 per cent of the total starch in 5 minutes. 

 (Chart D 626.) 



The hilum and lamellae are not visible in many of the 

 grains but in others the hilum is moderately distinct. 

 A narrow and not very refractive band is formed about 

 the margin of the grains before gelatinization. Gela- 

 tinization begins at the distal margin, as in C. vestita 

 var. rubro-oculata and all the grains show some tendency 

 for the process to begin at several disconnected points as 

 in C. rosea, but in most of them this is confined to 

 the distal margin or what is probably the distal margin. 

 The progress of gelatinization in most of the grains is the 

 same as that described in the second method under C. 

 vestita var. rubro-oculata, and in the rest it is the same 

 as that described under C. rosea. The gelatinized grains 

 are large and very much distorted, and show but little 

 resemblance to the form of the untreated grain. In this 

 reaction the grains show qualitatively a closer relation- 

 ship to C. vestita var. rubro-oculata than to C. rosea. 



46. Starches of Calanthe vestita vae. rubro- 

 octjlata, c. regnieri, and c. bryan. 

 C. vestita var. rubro-oculata (seed parent) is de- 

 scribed on pages 772 to 775. 



Starch of C. reonieri (Pollen Parent). 



(Charts D 627 to D 634.) 

 Histologic Pkopebties (See Foot-note, page 769). 



In form most of the grains appear to be simple and 

 isolated with the exception of rare aggregates consisting 

 usually of 2 components. As the hilum is usually absent 

 it is difficult to -assert definitely that the grains are gener- 

 ally simple. Compound grains were not observed. Well- 

 defined pressure facets are not present, probably due to 

 the greatly compressed lateral surfaces, but occasionally 

 a broadened or irregular concave distal end is noted, but 

 is not nearly so clearly defined as in C. vestita var. rubro- 

 oculata. The surface of the grain is generally irregu- 

 lar, much more irregular than in C. vestita var. rubro- 

 oculata. In addition to the irregularities found in C. 

 vestita var. rubro-oculata may be mentioned the follow- 

 ing: either an entire or distal crenate margin and a 

 small nipple-like protuberance at the proximal end. The 

 conspicuous forms are nearly round, pure, and with nar- 

 row end, curved pyriform, and ellipsoidal. The addi- 

 tional forms are reniform, round, pure ovoid, ellipsoidal 

 with squared or irregular distal end, imperfect rhom- 

 boidal, plano-convex often with rounded protuberances 

 in center of plane surface, and grains of indefinite shape. 

 The conspicuous forms of the separated grains are dome- 

 shaped, often with irregular distal end, and broad pyri- 

 form. Most of the grains above enumerated have either 

 a sinuous or crenate margin, the latter frequently more 

 marked at or confined to one end. The majority are 

 much broader and more flattened than in C. vestita var. 

 rubro-oculata, and when viewed on edge they are usually 

 narrow lenticular, narrow ellipsoidal, and rod-shaped. 

 A few scattered grains are found which are larger than 

 in C. vestita var. rubro-oculata and not much flattened. 



The hilum is not usually demonstrable and when 

 it can be seen is much less distinct than in C. vestita var. 

 rubro-oculata, and is a small round, non-refractive spot. 



A delicate transverse fissure may be present at the hilum, 

 and either 1 median or 2 longitudinal fissures emerge 

 from the hilum and proceed distalwards. When 2 are 

 present they may be directed obliquely towards the distal 

 corners, but in narrower grains they often soon become 

 so deflected as to be nearly parallel with one another; 

 these fissures are usually non-refractive. Definite fis- 

 sures connected with the hilum are less frequent than in 

 C. vestita var. rubro-oculata, and when present lack the 

 refractivity usually found in that species. The main 

 body of most of the grains is composed of a refractive 

 mass which is broken into fragments or large granules, 

 either by a network of translucent lines or by translucent 

 dots which impart a pitted appearance to this region of 

 the grain ; such grains were not found in C. vestita var. 

 rubro-oculata. The position of the hilum varies from 

 centric to quite eccentric; the range of eccentricity 

 being 0.46 to 0.1, more frequently 0.25 of the longitudinal 

 axis. Since the hilum is rarely demonstrable these figures 

 must be considered provisional. 



The lamella are not usually demonstrable, much less 

 frequently than in G. vestita var. rubro-oculata. The 

 surface of a few scattered smaller grains is homogeneously 

 refractive, rarely with 1 distinct lamella near the hilum, 

 and such grains closely resemble those commonly found 

 in C. vestita var. rubro-oculata. In the main body of 

 most of the grains no lamellae are demonstrable, but this 

 region is heterogeneously refractive as already described, 

 and is bounded by a narrow very refractive marginal 

 border which is frequently composed of but 1, rarely 2 

 or 3 lamellae ; in the more slender grains this border is 

 generally lacking at the distal margin ; such grains were 

 not observed in C. vestita var. rubro-oculata. Since the 

 lamellae can not be counted throughout the grain, no 

 number can be stated. 



The size varies from the smaller grains, which are 10 

 by 6/x, to the larger, which are 36 by 34/* in length and 

 breadth, commonly about 24 by 23/a in length and 

 breadth. The grains are exceedingly light, which may 

 explain the comparatively large size of the smaller grains, 

 as the smallest have probably not been precipitated. 



Polariscopic Properties. 



The figure varies from centric to quite eccentric, 

 but very few grains occur in which it is distinct, much 

 fewer than in C. vestita var. rubro-oculata. When dis- 

 tinct the lines have the same arrangement and are as 

 fine as in C. vestita var. rubro-oculata. The usual 

 arrangement resembles a square or rectangular box, the 

 corners of which are always pierced and sometimes the 

 sides at one or more points. No clearly defined double 

 and multiple figures are observed. 



The degree of polarization is generally absent or very 

 low in the mesial portion, simply present at the margin 

 which is usually high (value 35). Pare grains occur 

 in which polarization is distinct throughout, and varies 

 from high to very high. The mean is much lower than 

 in C. vestita var. rubro-oculata. A variation is also 

 found in the same aspect of a grain as in C. vestita var. 

 rubro-oculata, and also in the sides of the box arrange- 

 ment mentioned under figure. 



With selenite the entire quadrants are rarely ob- 

 served ; when present they vary as in C. vestita var. rubra- 



