ABSTRACT
Macromorphological changes refer to modifications that can be detected simply with a dissecting microscope without any sectioning of the apex, although measurement of some of these changes is facilitated by the use of sections. Precisely timed measurements of morphological changes at the shoot apex during the floral transition indicate that flower formation is usually accompanied by several macroscopic changes which are often regarded as "symptoms" of flowering. Early workers, although handicapped by relatively crude techniques, had already made a number of very interesting observations on the macroscopic "symptoms" of flowering, apart from the formation of flower buds. They found that, at the start of reproductive development, the growth pattern at the shoot apex is profoundly modified, and the form of the plant changes accordingly. These modifications may be so uniform and typical that it is sometimes possible to recognize the symptoms and to diagnose the onset of flowering before flower buds become visible macroscopically.
