PROPAGATION. 



331 



venience of getting- at the pollinia, or in applying them 

 to the stigma, without injury or seriously manipu- 

 lating the flowers operated upon, when the sexual 

 organs are deeply seated in a narrowly tubular 

 perianth as in Masd&vallia amabilis, M. Veitchii, and 

 those species of Cattlcya or Leelia where the column 

 lies almost or quite close on the labellum. The 

 readiest means in the latter case would he to depress 

 the labellum with one hand, and apply the pollinia 

 with the other. A small, neatly-pointed forceps, or 

 pencil-like instrument, with which to remove the 

 pollinia from one flower and apply them to another, 

 would be convenient. In the case of Vanilla, some 

 manipulation is necessary in order to effect fertilisa- 

 tion, but on the other hand, Onciclium, Odontoglossum, 

 together with many of the finest genera, offer the 

 greatest facilities for performing the operation. 



Amongst Orchids, perhaps, there is no more re- 

 markable case than that of Catasetum. The 

 rostellum is prolonged into two slender, sensitive 

 processes known as antennae, which, when touched, 

 have the power of rupturing the anther, and the 

 strongly-elastic pedicles of the pollinia straightening 

 themselves, eject the pollen-masses with considerable 

 force. The object here is to secure the pollinia 

 and prevent their being lost. The flowers of the 

 genus are male, female, and hermaphrodite. The 

 females are devoid of antennas, and the viscid stigma 

 is large and easily accessible. The pollinia are re- 

 markable for the enormous size of their gland, by 

 which they attach themselves to whatever object, 

 insect or otherwise, they happen to strike when 

 ejected from the anther-cases. 



The great object in all these elaborate contri- 

 vances, and the highly modified organs in the whole 

 Orchid order, is to secure the safe transfer of the 

 pollen from one flower to another, with the least 

 possible loss, which means conservation of energy. 

 The pollen, moreover, is valuable on account of the 

 quantity required to fertilise the thousands of ovules 

 present in the ovary. 



A small, but not the least important group, the 

 Gypripedim, includes the remaining genera of the 

 order. Here, in opposition to all the other groups, 

 the stigmatic surface is convex and dry, while the 

 glutinous and granulose pollen effects the union or 

 adhesion of one to the other, aided, no doubt, by 

 the roughness or looseness of the tissue of the stigma 

 itself. The slipper of Cypripeduon is another 

 splendid piece of mechanism or contrivance, by 

 which fertilisation is insured in one of two ways, 

 according to the direction an insect inserts its 

 proboscis, so as to fertilise it with its own pollen, or 

 failing that, to carry the pollen to another. There 

 are two fertile anthers belonging to an inner series 

 of three in this group, and owing to their position at 



an opening near the base of the labellum, they are 

 readily accessible and removable, when, by gently 

 depressing the labellum of the same or another flower 

 it is intended to fertilise, the convex inner surface 

 of the stigma, which lies immediately behind the 

 staminode, can easily be reached so as to apply the 

 pollen. 



How and when to fertilise are vital points of 

 practice that only considerable experience can solve. 

 The flowers of Orchids remain a long time in a 

 fertilisable condition, and they attain this state 

 shortly after they are fully expanded. The general 

 appearance, together with the odour arising from 

 fragrant species, the viscidity of the stigmatic disc, 

 and the readily removable pollinia, are all distinctive 

 marks that fertilisation may be effected. If this has 

 happened it will very soon be indicated by the early 

 fading of the perianth. It does sometimes, though 

 not frequently, happen.that the pollinia are removed 

 by insects in our hot-houses, consequently^the careful 

 hybridist will protect the fertilised flowers till all 

 danger from the possible access of other pollen is 

 averted, and at the same time accurately tabulate 

 his experiments. 



The following extracts are from a valuable paper 

 read by Mr. H. J. Veitch at the Orchid Conference, 

 held at South Kensington, Wednesday, May 13th, 

 1885. " It was Mr. John Harris, a surgeon of Exeter, 

 who suggested to Dominy the possibility of muling 

 Orchids, and who pointed out to him the repro- 

 ductive organs situated in the column, and showed 

 that the application of the pollinia to the stigmatic 

 surface was analogous to the dusting of the stigma of 

 other flowers with pollen. This simple fact being 

 once fairly grasped, the work of fertilisation pro 

 ceeded apace. The flowers of showy species of 

 Cattleya, Leelia, CalaMhc, &c, were fertilised with 

 the pollinia of other species, and even the 

 flowers of supposed different, but of course allied 

 genera, were also operated upon in the same way. 

 Capsules were produced in abundance, which in due 

 course proved their maturity by dehiscing, and thus 

 the long and anxiously desired seed was at length at 

 hand. 



" Among Cypripeds some very curious facts have 

 been elicited through muling. Thus, the East Indian 

 species cross freely with each other, and a numerous 

 progeny has resulted therefrom. The South Ameri- 

 can species, the Selenipedia, as they are called, 

 also cross freely with each other, and many new 

 forms have been obtained ; the hybrids in both 

 sections flower within a few years of the seed being 

 sown. But in the case of the crossing of Indian 

 with South American species, the process has been 

 much slower in producing results. An infinitely 

 smaller percentage of the seed genninates, and those 



