62 
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY, 
OBSERVATIONS ON SOME OF THE PLANTS EXHIBITED. 
By the Rev. Professor George Henslow, M.A., V.M.H. 
[June 5, 1900.] 
Orchids. — Mr. Henslow first described the process of fertiHsation m- 
Orchis Morio, exhibited by Mr. Wallace ; and also that of Phal(Bnopsis 
grandiflora. He called attention to some fine blossoms of CatUeya 
labiata Warnerii, sent by Mr. Jas. Douglas, to show that Orchids do not 
degenerate if properly treated ; for the plant from which they were 
gathered was a portion of one exhibited by Mr. Rucker in 1866. 
Mr. Henslow alluded to a paper by M. Noel Bernard* upon the 
germination of Orchids, which has always been a matter of great 
difficulty. This has arisen from the fact that the seeds, which are 
always in an arrested pro-embryonic condition, will not germinate unless 
a particular microbe is in the soil, which is required for a symbiotic 
existence. M. Bernard states that little difficulty is met with if the 
seeds of any species be sown on the soil in wJiich a plaitt of that species 
has been groiving, as it is impregnated with the particular microbe 
required. 
Streptocarpus. — The original species, S. polyanthus, with small 
insignificant flowers, was shown for comparison with the resulting 
hybrids of much finer quality raised by Mr. Yeitch. 
Ornithogalum arabiann. — Fine specimens were sent by Mr. Wallace.. 
Mr. Henslow remarked that in Malta the Maltese are very careless in 
removing "weeds" from their fields, so that he had collected large 
quantities of this flower, as well as of Gladiolus, Blue Anemones, 
Pheasant's- eye, Oxalis cernna, &c., for decorative purposes, all being 
troublesome "weeds." 
Helianthemum. — A plant of this genus afforded an illustration of 
rapid motion being exhibited by the stamens, for when lightly grasped 
and then let go they all spread out upon the petals. 
P.EONIA. — The only British species, P. corallina, which formerly grew 
on Steep Holmes, an island off the mouth of the Severn, was usually 
regarded as "introduced," but Mr. Henslow observed that as it is a 
Mediterranean plant it may possibly have belonged to the small group 
which passes from the Riviera to Normandy, and are thence found 
reduced in numbers in the Channel Islands, while a few occur in the 
South-west of England and up the West Coast. They thus became 
isolated when the English Channel was formed and severed England' 
from the Continent. 
Effect of Stock on Scion. — Dr. Bonavia sent examples of flower- 
ing shoots of Gytisus Adami, and Mr. Henslow explained the well-known 
origin of the dissociation of G. Laburnum from G.pwyureus on the same 
tree. As another influence of stock on scion he referred to Mr. Heal's 
experience in grafting certain hybrids of the greenhouse Rhododendrons- 
* lievuc Gineralc dc Botanicjiie, March 1900. 
