CROSS FERTILISATION. 



53 



are at first almost invisible to the naked eye. Their subsequent removal and treatment 

 requires the greatest care and watchfulness, for a cold draught of air, an overdose or an 

 insufficiency of moisture, or a bright ray of sunshine, will kill them outright. They 

 must at first be pricked out around the edges of small pots in sterilised compost, and 

 subsequently with great care placed singly in the smallest-sized pots obtainable, 

 these plunged in moss in pans, and the growth of the seedlings continued without check 

 until the flowering size is reached. 



Some of the most successful hybridists of the present day are turning their attention 

 to the raising from seed of some of the rare and valuable orchids, and by this means 

 obtaining a large stock ; this time-involving process is not worth the trouble, with such 

 as are already plentiful and cheap. The seed is obtained by fertilising flowers with their 

 own pollen or that of another flower on the same plant. Bigeneric hybrids are raised 

 by crossing species of different genera, such as Lselia cinnabarina, and Cattleya Mossise, 

 which gave the beautiful Lselio- Cattleya Hippolyta. The genera crossed usually bear 

 some affinity to each other. For instance, cattleyas cross freely with laslias, sophronitis, 

 or brassavola, and the seedlings show the fusion of blood, so to speak. Epidendrums 

 cross with sophronitis and many other related genera, but no one would expect them to 

 cross with a cypripedium or other far-removed genus. There are even species in the same 

 genus that do not freely cross, and for many years it was found impossible to cross a 

 deciduous dendrobium with an evergreen one, though this has now been accomplished. 



Inexperienced persons who would like to practise the art of pollination should 

 examine carefully the illustrations on page 33, Vol. I., by Mr. F. W. Burbidge, and read 

 attentively the matter that is there to be found on the subject. His sketch representing 

 natural, or insect, fertilisation is repeated on the preceding page, as it is elucidatory of 

 the prominent parts of a typical orchid flower. 



POTTING AND BASKETING. 



In potting and basketing orchids, quite a different mode is followed from that 

 practised for other plants, and, before describing it in detail, it will be well to consider 

 what an orchid requires in the way of a rooting medium. By far the majority of the 

 species we cultivate are epiphytes ; they have their host plants or trees in their native 

 haunts, and to these they fasten themselves by their roots, but it is merely a mechanical 

 support. They are not parasites, and draw no support of a nutritious character from the 

 trees they affect. 



