MILTONIA. 



757 



grains of the aggregate type are dome-shaped with either 

 squared, diagonal, concave or irregular distal end; 

 polygonal; finger-shaped with concave distal end, and 

 bell-jar-shapcd with either squared or concave distal end. 

 The conspicuous forms of aggregates are potato-shaped 

 (a mosaic of varying numbers of components), rounded 

 mosaic, doublets of about equal components, triplet in 

 linear arrangement (the central component the largest), 

 doublets and triplets consisting of 1 large component and 

 either 1 or 2 of moderate size located usually at the distal 

 end, rarely at the proximal. The grains are not usually 

 flattened, about as in M. vexillaria, the extension later- 

 ally by secondary lamellae being less frequent than in 

 M. razlii. In form the grains of AI. bleuana are closer to 

 those of M. vexillaria than to M. nvzlii. 



The hilum when unfissured is more distinct than in 

 both parents; clefts appear with slightly less frequency 

 than in M. vexillaria, and are considerably less numerous 

 than in M. rcczlii. The hilum is often observed as either 

 a small, lenticularor round, non-refractive to quite refrac- 

 tive spot, and is refractive with much more frequency 

 than in either parent. Either a small round or an 

 irregular cavity appears, more often than in both parents. 

 Clefts of a similar character to those of both parents are 

 present, being deeper but about as frequent as in M. 

 vexillaria, about as deep but not quite so often observed 

 as in M. nvzlii. The fissures which leave the hilum are 

 about the same as in M. vexillaria, they appear with less 

 frequency, especially the median longitudinal one, than in 

 M. razlii. The eccentricity varies from 0.61 to 0.1, 

 commonly 0.33 to 0.2, of the longitudinal axis, nearly 

 the same as in M. rcezlii and less than in M. vexillaria. 

 In the character of the hilum M. bleuana is closer to M. 

 vexillaria, but in degree of eccentricity it is much closer 

 to M. rcezlii. 



The lamella; are more frequently demonstrable than 

 in both parents. The lamelhe of the primary set have, 

 in general, the same characteristics and arrangement as 

 noted for both parents. The border with laterally ex- 

 tended distal corners inclosing an ellipsoidal grain is 

 somewhat more frequently observed than in M. vexillaria, 

 but considerably less frequently than in M. rcezlii. There 

 is some variation in the direction of groups of lamellae, 

 probably due to a shifting of the longitudinal axis, more 

 than in M. vexillaria, but considerably less varied than in 

 M. razlii. A definite secondary set of lamella; are some- 

 what more frequent than in M. vexillaria, but much less 

 than in M. razlii. A variation is seen in the direction of 

 groups of lamellae, usually only 2 as in M. vexillaria, but 

 occurring with more frequency than in M. vexillaria; a 

 variation in character of the groups is less frequently 

 well marked and they are considerably less often observed 

 than in M. razlii. In the character of the lamella; M. 

 bleuana is closer to M. vexillaria than to M. razlii. 



The size of the grains varies from the small which 

 are about 5 by 4/*, to the larger which are about 50 by 

 26/x, commonly about 32 by 28/i, in length and breadth. 

 The grains of M. bleuana are larger than those of either 

 parent, but are closer to M. rcezlii than to M. vexillaria. 



PoLARiscoric Properties. 

 The figure varies from centric to quite eccentric, a 

 smaller proportion of the ccentric than in M. vexillaria 

 making the mean not quite so eccentric, a larger propor- 



tion of the quite eccentric than in .1/. rcezlii, hence the 



mean is more eccentric than in .1/. rmzlii. The figure 

 is slightly less clean-cut than in M. vexillaria, but more 

 than in M. razlii. The lines are generally line though 

 somewhat more frequently coarse than in M. vexiilana, 

 but not. so often as in .1/. rcezlii. The lines usually cross 

 either at right angles or obliquely, but when coarse may 

 occasionally be arranged in a median line with bisected 

 ends, the I'onnci- as in both parents, but the latter was 

 never noted when the medium line is line or as line as 

 sometimes found in M. vexitlaria and more frequently in 

 M. razlii. The lines are generally straight, often with 

 broadening towards the margin, but may be bent and 

 bisected, less frequently bent, but with more bisection 

 than in both parents. More double and multiple figures 

 than in both parents. 



The degree of polarization is high to very high (value 

 88), with more of the latter than in either parent, hence 

 making the mean higher. A variation in the same aspect 

 of a grain is not usually present, less than in both parents. 



With selenite the quadrants arc usually sharply de- 

 fined, slightly less often than in M. vexillaria, but found 

 much more frequently than in both parents. They are 

 often unequal and slightly irregular, but more frequently 

 equal and regular than in both parents. The colors are 

 generally pure; the impurity when present is usually in- 

 dicated by a greenish tinge to both colors; the colors are 

 more frequently pure than in both parents. 



In degree of polarization, character of the figure, and 

 appearances with selenite M. bleuana is closer to M. 

 vexillaria than to M. razlii. 



Iodine Reactions. 

 With 0.25 per cent Lugol's solution the grains color 

 a moderate blue-violet (value 55), which is the same as 

 in M. vexillaria, but a little deeper and less violet than 

 in M. razlii; the color deepens rapidly, becoming moder- 

 ately deep to deep and more bluish in tint; there is 

 more variation with the mean scarcely so bluish nor so 

 deep as in M. vexillaria, but less variation, with the mean 

 more bluish and deeper than in M. razlii. With 0.125 

 per cent Lugol's solution the grains color a light blue- 

 violet which is at first the same tint as in M. vexillaria but 

 slightly darker and more bluish than in M. razlii; the 

 color deepens with much variation, with the mean lighter 

 and less bluish than in M. vexillaria; the tint is the same 

 but with a little more variation, with the mean slightly 

 darker than in M. razlii. After heating in water until 

 all the grains are gelatinized and then adding 2 per cent 

 Lugol's solution, the gelatinized grains color moderately 

 to moderately deep indigo-blue, rarely with reddish tint, 

 a little lighter than in M. vexillaria and considerably 

 lighter than in M. razlii, fewer grains with reddish tint ; 

 and the solution is deeper than in both parents. If the 

 preparation is boiled for 2 minutes and then treated with 

 an excess of 2 per cent Lugol's solution, the grain-resi- 

 dues, which are somewhat more numerous than in both 

 parents, color a light to moderate blue, all with reddish 

 tint, lighter than in both parents ; the capsules, which are 

 much more frequently ruptured than in both parents, 

 generally color a light to moderately deep reddish-helio- 

 trope or amethyst, occasionally a light to deep old-rose, 

 lighter and considerably less reddish than in M. vexil- 



