146 MISSOURI BOTANICAL GARDEN BULLETIN 
ning, the cypripediums were almost exclusively used in 
hybridization ;" but at present the greatest activity exists 
among the more showy varieties of Cattleya, Laelia, Brassa- 
- vola and Odontoglossum. Owing to climatic conditions, 
work with representatives of the last mentioned genus is con- 
fined to the European countries. 
The laelia-cattleya hybrids, that is those in which a repre- 
sentative of the genus Laelia is crossed with one from the 
genus Cattleya—the so-called bigeneric hybrids—are well 
represented in all collections. Their characters, in most 
cases, are intermediate between those of the parents, especially 
as regards the pseudo-bulbs and leaves. Occasionally when 
a monoplyllous species of Cattleya or Laelia is crossed with 
a diphyllous form, some of the stems, or pseudo-bulbs of 
the offspring have but one leaf, whereas others have two, 
no definite law apparently being followed. 
In cypripedium hybrids the parents can readily be recog- 
nized by the leaf and floral characters, especially where 
Cypripedium Spicerianum or C. farrieanum have been used 
in the crosses. The production of hybrids between species 
of Brassavola and Cattleya is receiving more attention at 
the present time, and those which have been realized repre- 
sent a distinct improvement over the the laelia-cattleyas. A 
good specimen of “Brasso-Cattleya Maronae” in the Garden 
collection was in flower last May. In this bigeneric hybrid, 
produced by crossing Brassavola Digbyana with Cattleya 
gigas, the shape of the flower, manner of growth, the large 
fimbriated lip and dark green succulent leaves plainly sug- 
gest the Brassavola parentage, whereas the light mauve color 
of the flowers and the elongated leaves and pseudo-bulbs indi- 
cate, rather, the Cattleya stock. 
Seedlings. The seeds of orchids are exceedingly minute, 
so minute in fact that a microscope is usually required for 
their examination. Darwin estimated that a representative 
seed pod of an orchid contained 1,000,000 seeds. Although 
these minute bodies are not provided with winged a pend- 
ages or feathery hairs as are the seeds of the maple and 
dandelion, they nevertheless are disseminated by the wind 
because of their extremely small size and weight. Even in a 
greenhouse, where the air currents are slight, these diminu- 
tive seeds are carried for considerable distances. 
Raising orchids from seed is a very slow process, about — 
five pees elapsing from the date of pollination to’ 
the flowering of the arg In one instance a cattleya 
_ was crossed with the pollen of an epidendrum on November _ 
