41 8 GENERAL REVIEW. 



is widely distended previous to fertilisation ; but as soon as that 

 actually takes place, the sides begin to contract, and finally 

 close in, in some cases even overlapping, and thus effectually 

 preventing the possibility of the pollen being removed by in- 

 sect or other agency, or becoming damaged by water or other 

 foreign body coming in contact with it. The ovary enlarges 

 rapidly after fertilisation ; the capsules of Phalaenopsis, which 

 are rarely half an inch long before, attain a length of from 4 to 

 6 inches, and the thickness of the little finger, in about sixty 

 days after that has taken place, and contain many hundreds of 

 minute ovules. The great difficulty, however, does not lie in 

 the mere fertilisation, but in obtaining a fair percentage of seed- 

 lings. The structure of Orchid seeds is nearly the same as those 

 of Burmanniads and Pyrolads or Winter Greens; they consist of 

 one or more finely-netted or cellular hygrometrical coats of an 

 oblong form, something like an old-fashioned chain purse, while 

 the nucleus may be likened to a small rounded or oblong gold 

 coin inside. The seed-coats are transparent in nearly all the 

 species, if we except Vanilla, where they are more dense and 

 scobiform, like those of Nepenthes in colour, and perfectly 

 opaque. Seen under the microscope, the seeds of most Or- 

 chids form beautiful objects. It is generally thought that all 

 Orchids are epiphytal in their .earliest stages of germination ; 

 hence the desirability of sowing their seeds on living moss or 

 other vegetation, which will supply moisture regularly to their 

 hygrometrical tissues. As before mentioned, it is requisite for 

 the parent plant to be in the highest state of health, in order to 

 produce seed in good condition. In order to favour the pro- 

 duction of well-developed seeds as much as possible, the hy- 

 bridiser should be content to take only a small quantity from 

 each seed-parent, however vigorous it may be. I have re- 

 peatedly noted in the course of my own experiments that one 

 pod on a vigorous Cattleya or Phalaenopsis is quite sufficient 

 to stop the growth of the foliage for a whole season ; and this 

 does not appear so surprising when we consider that each cap- 

 sule contains thousands of hungry little ovules, which collec- 

 tively require a deal of nourishment.* 



After many careful experiments, I have come to the conclu- 

 sion that perfect seeds are produced much more rarely than is 

 generally supposed ; indeed, I believe Orchids produce good 

 seed but very seldom, especially if more than one capsule is 

 left on a plant, and to this may be attributed the many failures 



* Valuable notes on the structure and gerrnination of Orchid seeds are 

 given in'Beitrage zur Morphologic und Biologic der Familie der Orchideen,' 

 by M. J. G. Beer. (See also 'Revue Horticole,' 1872, p. 244 and 331.) 



