RALPH R. KIESEWETTER 
Of 
Kiesewetter Orchid Gardens 
begs to announce that, beginning in 1952, a basically new plant-breeding policy 
has been effected. Pursuant with the tenets of a rigid research program, only 
crosses from laboratory-controlled stud plants will be allowed on the market. 
Henceforth, all seedlings will bear the stated cytological composition of either 
parent. 
Au Introductory Note 
by 
Dr. James A. de Tomasi 
Research Consultant 
Akin to any other vegetating organism, the orchid plant is made up of living 
tissues. Tissues, in turn, consist of myriads of individual microscopic cells, each 
organized as a basic unit, distinct yet clearly dependent upon all others. Why is 
the cell so significant a unit? Within the sustaining enclosure of the cell wall 
floats, amidst other constituents, an all-important small body, the cell nucleus. 
Here is where specialized micro-technique and high-power microscopy come in 
to help open wider horizons in the search for the orchid of the future. 
The nucleus is largely made up of a protein-like substance, the chromatin, 
so named for its high affinity for biological dyes used in its detection and identi- 
fication. When a cell is about to divide (as they all do, a ceaseless process that 
goes on as long as tissues continue to grow), the nucleus undergoes profound 
changes. Its chromatin, from a seemingly unorganized granular mass, gradually 
assumes definite shape in the form of separate minute bodies somewhere of the 
order of one-thousandth of an inch or so in length. These are the chromosomes, 
the carriers of hereditary units, whose shape and size and number are important 
differential characteristics. [he transmission of hereditary characters from 
parents to progeny is exclusively the function of chromosomes in specialized 
cells, the sex cells of flower bud tissue. 
