326 



NATURE 



\August 3, 1882 



Now, the earliest ray-florets would naturally be bright 

 yellow, like the tubular blossoms of the central disk from 

 which they sprang. And to this day the ray-florets of 

 the simplest corymbiferous types, such as the corn-mari- 

 gold (Chrysanthemum segetum), the sun-flower (Helianthus 

 aumtiis), and the ragwort (Senecio jacobced), are yellow, 

 like the central flowers. In the camomile, however, the 

 ox-eye daisy, and the may-weed (Anlhe/nis cotula, Chrys- 

 anthemum leucanthemum, &c), the rays have become 

 white ; and this, I think, fairly establishes the fact that 

 white is a higher development of colour than yellow ; for 

 the change must surely have been made in order to attract 

 special insects. In the true daisy, again (Bellis perennis). 

 the white rays become tipped with pink, which sometimes 

 rises almost to rose-colour (Fig. 16) ; and this stage is exactly 

 analogous to that of apple-blossom, which similarly halts 

 on the way from white petals to red. In our own asters 

 (A. tripoiium, &c.) and the Michaelmas daisies of Ame- 

 rica, we get a further advance to purple, lilac, and mauve, 

 while both in these and in the chrysanthemums, true 

 shades of blue not infrequently appear. The Cinerarias 

 of our gardeners are similar forms of highly-developed 

 groundsels from the Mediterranean and the Canary 

 Islands. 



Tubular flowers with an irregular corolla are obviously 

 higher in their mode of adaptation to insect visits than 

 tubular flowers of the ordinary symmetrical type. 

 Amongst them, the first place must be assigned to the 

 Labiates. Not only are they deeply tubular, but they are 

 very bilateral and irregular indeed, displaying more modi- 

 fication of form than almost any other flowers except the 

 orchids. They mostly secrete abundant honey, and often 

 possess highly aromatic perfumes. Almost all of them 

 are purple or blue. Among the best known English species 

 are thyme, mint, marjoram, sage (Fig. 17), and basil, which 

 it need hardly be said are great favourites with bees. 

 Ground-ivy {Nepeta glechoma) is bright blue ; catmint 

 (Nepeta eeitaria), pale blue ; Prunella, violet-purple ; and 

 common bugle {Ajuga reptaus), blue or flesh colour. 

 Many of the others are purple or purplish. It must be 

 added that in this family the flowers are very liable to 

 vary within the limit of the same species ; and red, white, 

 or purple specimens are not uncommon in many of the 

 normally blue kinds. 



The Scrophularinete, and other allied irregular tubular 

 families are mostly spotted, and so belong to a later stage 

 of our inquiry ; but even amongst this group, the Veronica 

 genus has almost always pure blue flowers ; foxglove 

 (Digitalis purpurea) is purple; and many of the Broom- 

 rapes (Orobanchacea) are more or less bluish. Blue and 

 lilac also appear abundantly in spots or stripes in many 

 species of Linaria, in Euphrasia, and in other genera. 



We have given so much consideration to the Dicoty- 

 ledons that the relatively simple and homogeneous Mono- 

 cotyledons need not detain us long. Their coloration is 

 as a whole both less complicated and less instructive. 



The AHsmacea answer very closely to the Ranun- 

 culacecB, as being in all probability the earliest surviving 

 type of entomophilous Monocotyledons. Their arrange- 

 ment is of course trinary, but they have similarly separate 

 carpels, often numerous, surrounded by one, two, three, 

 or many rows of stamens, and then by one row of three 

 petals and one row of three sepals. All our English 

 species, however, are white or rosy, instead of yellow. 

 As they are marsh plants, they seem to have reached 

 or passed the stage of Ranunculus aquatilis. One species, 

 A/isma plautaga, the water-plantain, however, still retains 

 a yellow claw to the petals, though the limb is white or 

 pale pink. So also does Damasonium stellatum. These 

 two interesting plants present a remarkable analogy to 

 the water-crowfoot. 



Among monocotylcdonous families with a united ovary, 

 the Liliacea are probably the most primitive. Their 

 simplest type in England is Cagea lutea (Fig. 18), a yellow [ 



lily looking extremely like a bunch of Ranunculus Ficarta. 

 In Lloydia seroiina, a closely allied but more developec 

 form, the petals are white, with a yellow base, and three 

 reddish lines. The wild tulip is likewise yellow. Allium 

 ursinum, a somewhat higher type, is pure white. The fritil- 

 lary (Fritillaria Meleagris, Fig. 19), a large, handsone, 

 bell-shaped flower, with separate petals converging in;o a 

 campanulate form, and with a nectariferous cavity at 

 their base, is purple or red, checquered with lurid marks ; 

 but it often reverts to white, or even to a faint yellow. 

 In Scilla, however, including our common wild hyacinth 

 (S. nutans), the deep tubular flowers, composed of 

 perianth pieces with long claws, are usually blue, rarely 

 pink or white ; while in Hyacinthus and Muscari, which 

 have a united bell-shaped or globular blossom, formed by 

 the coalescence of the sepals and petals, dark-blue and 

 ultramarine are the prevalent tones. Meadow saffron 

 (Colchicum aiitumna/e), which has also a united tube and 

 very deep underground ovary, is a fine reddish purple : 

 its stamens secrete honey. 



The Iridecc and Amaryllideec are more advanced than 

 the lilies, in that they possess inferior ovaries — in other 

 words, their perianth tube has coalesced with the walls 

 of the inclosed carpels. In many cases, especially in the 

 more highly-developed species, their flowers are red, blue, 

 or purple. Triehonema Bulbocodium is purplish-blue, 

 with a yellow centre. Our two native crocuses (C vernus 

 and C. nudiflorus) are also purple. Sisyrinchtum Bennn- 

 dianum is a delicate blue. Gladiolus communis is brilliant 

 crimson. Iris fatidhsima is violet. Our own Amaryllids 

 are white or primrose, but brilliant reds and purples, as 

 well as highly-developed spotted types, are common 

 amongst the cultivated exotics. 



The Orchidaeea stand at the head of the entomophilous 

 Monocotyledons by virtue of their inferior ovary, their 

 irregular flowers, and their extraordinary adaptations to 

 insect fertilisation. Purples are the prevailing ground- 

 tones (Fig. 20) ; but in the commonness of variegation 

 and of specialised lines or spots of colour, the Orchids 

 answer closely to the Scrophttlarinea among Dicotyle- 

 dons, and may therefore best be considered in a succeeding 

 section. Grant Allen 



{To be continued.) 



A STRONOMICAL OBSER VA TORIES > 



AMONG the contributions of public and private munifi- 

 cence to the advance of knowledge, none are more 

 worthy of praise than those which have been devoted to 

 astronomy. Among all the sciences, this is the one which 

 is most completely dependent upon such contributions, 

 because it has the least immediate application to the wel- 

 fare of the individual. Happily, it is also the science of 

 which the results are best adapted to strike the mind, and 

 it has thus kept a position in public estimation which it 

 could hardly have gained if it had depended for success 

 solely upon its application to the practical problems of 

 life. That the means which have been devoted to its 

 prosecution have not always been expended in a manner 

 which we now see would have been the best, is to be ex- 

 pected from the very nature of the case. Indeed, a large 

 portion of the labour spent in any kind of scientific re- 

 search is, in a certain sense, wasted, because the very 

 knowledge which shows us how we might have done better 

 has been gained through a long series of fruitless trials. 

 But it is due both to ourselves and the patrons of astro- 

 nomy that as soon as any knowledge bearing upon the 

 question of the past application'of money to the advance 

 of science is obtained, use should be made of it to point 

 out the mistakes of the past and the lessons for the future. 

 It is now patent to all who have made a wide study of the 

 subject that large amounts have been either wasted or 

 applied in ways not the most effective in the erection and 



1 From the North American Rfvitw. 



