vi 
The genera most largely represented are the following :— 
Odontoglossum --»  «» about 350 entries. 
Cypripedium eat te 
Cattleya he ie oh Oe ae 
Dendrobium ata È of ee ee 
Leelia ... ae poe et ae. | ae 
Masdevallia . i: sO 
Oncidium sq: ae a 
Croton, Iris ... “: 2003 eek 
With regard to Odontoglossum a great number of forms and 
even of species previously undescribed have been introduced 
from the high Andes. Our knowledge of the genus has been, in 
fact, about doubled during the period covered by the list. None 
of the forms enumerated in the list have originated in cultivation. 
The art of the gardener has added to botanical science the 
knowledge of a considerable number of bigeneric hybrids, t.e., of 
crosses between species belonging to distinct and even not very 
closely allied genera. It was at one time supposed that such 
crosses were either impossible, or, if possible, were a proof that 
the genera were not really distinct. Darwin had long, however, 
clearly shown that the limitations and possibilities of cross- 
fertilisation do not run parallel with taxonomic affinities, 7.¢., with 
the place occupied by the parents in a natural classification. It 
may be convenient to give the following list of bigeneric hybrids 
included in the list :— 
Aloe x Gasteria. 
Aphelandra x Stenandrium. 
Bertolonia x Sonerila. 
Calanthe x Limatodes. 
Chionodoxa x Scilla. 
Epilelia = Epidendrum x Lelia. 
Epiphronitis = Epidendrum x Sophronitis. 
Gloxinia x Tapeinotes. 
Lelio-cattleya = Lelia x Cattleya. 
Phaio-calanthe = Phaius x Calanthe. 
Sophro-cattleya = Sophronitis x Cattleya. 
Sophro-lelia = Sophronitis x Lelia. 
Spirea x Astilbe. 
Urceocharis = Ureeolina x Eucharis. 
Zygocolax = Zygopetalum x Lycaste. 
