576 



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



for a large minority of the grains of N. weardale perfec- 

 tion, the differences are that the material distal to the 

 hilum and the transverse furrows or fissures are not 

 distinctly fissured and seem to change gradually into a 

 finely granular mass, of which the separate granules are 

 hardly distinguishable, and there is not a striated lamel- 

 lated band all around the margin but only at the proxi- 

 mal end and sides nearby. The gelatinized grains are 

 more swollen, have as thin capsules, and are much more 

 distorted than in N. weardale perfection. 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 79 per cent of the 

 entire number of grains and 98 per cent of the total starch 

 in 2 minutes, and in about 98 per cent of the grains and 

 in more than 99 per cent of the total starch in 5 minutes. 

 (Chart D 328.) 



The hilum becomes distinct, attended by the forma- 

 tion of a small bubble in the majority of the grains. 

 The lamella? become distinct at first, but are soon ob- 

 scured. Gelatinization begins at the hilum and pro- 

 gresses according to two methods. In the first, which is 

 seen in a small majority of the grains, the material 

 which represents a primary starch formation and which 

 is immediately around the hilum is either divided into 

 first two and then four portions, which in turn are 

 divided into rather coarse refractive granules; or, after 

 being separated from the rest of the material of the grain, 

 which probably represents a secondary starch formation, 

 by a refractive fissure, remains unaffected until gelatini- 

 zation is complete, and then is gelatinized as a separate 

 part, the interior becoming granular and the marginal 

 material forming a homogeneous-looking refractive band 

 which is slowly gelatinized. This secondary material 

 surrounding the primary deposit loses its lamellar struc- 

 ture and becomes homogeneous-looking and more refrac- 

 tive, and then is divided into portions of unequal size by 

 concentric refractive fissures. After this it gelatinizes 

 very rapidly, with much swelling and distortion of the 

 capsule. If the primary starch has been divided into 

 coarse granules, these follow closely the swelling of the 

 secondary starch, becoming more and more widely separ- 

 ated as they do so, and at the same time gradually becom- 

 ing gelatinous. If it is not divided into granules, the 

 primary starch, as already described, gelatinizes as an 

 independent part. In the second method, which is seen 

 in a large minority of grains, two furrows or actual fis- 

 sures extend transversely or obliquely from the hilum to 

 the margin, and the starch distal to these fissures and to 

 the hilum loses its lamellar structure and becomes homo- 

 geneous-looking, and in certain circumscribed portions 

 more refractive. It then gelatinizes rapidly, with much 

 swelling and considerable distortion of the capsule. The 

 starch at the proximal end and sides nearby is meanwhile 

 coarsely striated and, as the grain swells, forms at the 

 proximal margin a coarsely striated band which is com- 

 paratively slowly gelatinized after the rest of the grain. 

 The gelatinized grains are much swollen, have rather 

 thin capsules, and are very much distorted. 



Comparison of the sulphuric-acid reactions between 

 N. madame de graaff and N. weardale perfection shows : 



A bubble is not so often formed at the hilum, and 

 the lamellae are as distinct as in N. weardale perfection. 

 Gelatinization follows in general the two methods de- 

 scribed in N. weardale perfection. The great majority 



of the grains follow that seen in a small majority of 

 the grains of N. weardale perfection, and the differences 

 are that the primary starch is not divided up into 

 granules, but swells as a separate part at the same 

 time that the secondary starch swells, following this 

 closely; or is first divided by coarse striae into a number 

 of cylindrical granules which in the same way closely 

 follow the gelatinization and swelling of the secondary 

 starch. Rarely the primary grain remains unaffected 

 until the secondary starch has gelatinized, and then it 

 gelatinizes as an independent grain. In the second 

 method, which is seen in but few of the grains, the differ- 

 ences noted are that the material distal to the hilum 

 and to the furrows extending out from it on either side 

 is divided by concentric refractive fissures which corre- 

 spond to the lines of the lamella? and then gelatinized 

 with considerable swelling and distortion, and the proxi- 

 mal starch is not so coarsely striated as in N. weardale 

 perfection. The gelatinized grains are more swollen, 

 have thinner capsules, and are more distorted than in 

 N. weardale perfection. 



Narcissus pyramus (Hybrid). 



(Plate 13, fig. 78; Charts D 323 to D 328.) 

 Histologic Properties. 

 In form the grains are usually simple and isolated. 

 There are as many compound grains and aggregates as in 

 N. madame de graaff, and they belong to the same types 

 as in that starch, the compound grains often containing 

 more components than do those of N. weardale perfec- 

 tion. There are as many simple grains in which both a 

 primary and a secondary starch formation can be seeu, 

 as in N. madame de graaff, and more than in N. weardale 

 pt rfection. The grains are as often irregular as in 

 N. madame de graaff and the irregularities are due to 

 the same causes. The conspicuous forms are ovoid, ellip- 

 tical, triangular with rounded corners, and nearly round. 

 The additional forms are jdano-convex, lenticular, irregu- 

 larly quadrilateral, and clam-shell-shaped. The forms 

 are as varied as in N. madame de graaff and more varied 

 than in N. weardale perfection. In form N. pyramus 

 shows a much closer relationship to N. madame de graaff 

 than to N. weardale perfection. 



The hilum when not fissured is not very distinct, as in 

 both parents. It is fissured as often as in N. iveardale 

 perfection, but no more deeply nor extensively than in 

 N. madame de graaff. The fissures have the same forms 

 as in the parents. The hilum is sometimes centric, but 

 in the majority of the grains it is eccentric from 0.45 to 

 0.29, usually 0.37, of the longitudinal axis. In the 

 character and the eccentricity of the hilum N. pyramus 

 shows a somewhat closer relationship to N. madame de 

 graaff than to N. weardale perfection. 



The lamella are usually not distinct, and are rather 

 fine, as in N. madame de graaff. In everything else they 

 are the Baioe as in both parents. The number counted on 

 some of the larger grains varies from 8 to 14, usually 10. 

 In the character of the lamellae N. pyramus shows a 

 somewhat closer relationship to N. madame de graaff than 

 to N. weardale perfection, but there are no marked dif- 

 ferences between either parent or hybrid. 



In size the grains vary from the smaller which are 

 3 by 3/x, to the larger which are 34 by 40/* and 44 by 44/*, 

 in length and breadth. The common sizes are 18 by 22/t, 



