Cross-fertilization must of necessity occur when the flowers are structurally unisexual, as in the hazel, in which the male and female flowers are monoecious, or separate on the same plant, and in the willow, in which they are dioecious, or on different plants.
Prakt.Chem., 1896, 53, pp. 169 et seq.) hold that the compounds are structurally different, the normal diazohydroxide being a diazonium derivative of the type R N(N) OH.
On the other hand, it is rich in Cornpositae, especially Solidago and A ster, Polemoniaceae, Asciepiadaceae, Hydrophyllaceae and Cyperaceae, and it has the endemic Sarracenia, type of a family structurally allied to poppies, of which of the remaining genera Darlingtonia is Californian, and Heliamphora Venezuelan.
This structurally facilitated a substantial expansion in the role of government.
In the Polychaeta, which are to be regarded as structurally simpler forms than the two groups just referred to, there is but little subdivision of the coelom of the segments, indeed a tendency in the reverse direction, owing to the suppression of septa.
Consequent disuse, and the transmission (as Lamarck would have supposed) of a more and more weakened and structurally impaired eye to the offspring in successive generations, until the eye finally disappeared.
In A pis the workers differ structurally from the queen, who neither builds cells, gathers food, nor tends brood, and is therefore without the special organs adapted FIG.
From comparative anatomy alone it is possible to arrange a series of living forms which, although structurally a convincing array because placed in a graded series, may be, nevertheless, in an order inverse to that of the actual historical succession.
An inland extension from the coastal plain in north-central Texas leads to a large cuesta known as Grand Prairie (not structurally included in the coastal plain), upheld at altitudes of 1200 or 1300 ft.
Each neuron or nerve cell is a morphologically distinct and discrete unit connected functionally but not structurally with its neighbours, and leading its own life independently of the destiny of its neighbours.