Cultural First Principles. 



By G. S. BOULGEE, F.L.S., F.G.S., late Trofessor of Natural History in the 

 Aguicultukal College, Cirencester. 



VII. — Flowers. 



(^Contimted from }xirje 677.) 

 The leaf is as important from the point of view of the '' transcendental/ 

 or comparative anatomist as we have seen it to l)o from that of the 

 physiologist, or student of the life processes of the plant. It is so 

 because it is the archetype of all the principal organs which constitute 

 the flower and fruit. These organs are, in fact, simply leaves which 

 have become modified for certain special functions. Thefloiccr con- 

 sists, speaking generally, of several circles or" whorls " of leaves, which 

 are concerned directly or indirectly with the reproduction of the plant 

 by means of seed. These leaves are, therefore, often destitute of chlo- 

 rophyll, or leaf green, and do not " fix" carbon from the atmosphere. 

 Their respiration, or inhaling of oxygen and exhaling of carbonic acid, 

 is consecjuently more easily observed than that of ordinary green 

 foliage leaves. 



What is said in this paper must be understood to apply solely to the 

 flowers of what are commonly called " flowering plants "-^-the " Phanero- 

 gams " of the botanist — and not to the reproductive systems of the 

 lower plants, fungi, seaweeds, mosses, and ferns. With the less easily 

 observed structure of these latter — the " Cryptogams " of the botanist — 

 no cultivators, save growers of mushrooms and ferns, need trouble 

 themselves. There is also considerable difference between the repro- 

 ductive organs of conifers and those of other flowering plants, which 

 will be more fully alluded to later; the present sketch must be 

 understood to treat of the latter — the '' Angiosperms " of botanists, or 

 those plants whose seeds are perfectly enclosed in a fruit. Let us take 

 a few types, a buttercup, a white water-lily, a violet, a bunch of lime 

 blossoms, a daisy, and a spike of foxglove to commence with. Under 

 each blossom of the foxglove we see a plain, green leaf; while the 

 stalk of the bunch of lime blossoms seems to spring from a broad, pale- 

 coloured leaf-like organ. In the well-known greenhouse plants the 

 Poinsettia and the Bougainvillea we find corresponding leaves round 

 the small flowers, but here they are gaily coloured. Still their veins 

 prove them leaves. Now the daisy blossom is a collection of numerous 

 small flowers crowded together at the end of the flower-stalk ; just as 



