FERTILIZATION. 261 
To assist in this, the viscous gland and its processes, but 
more especially the former, are placed on the most prominent 
part of the column, a part which must be passed to enable 
the insect to reach the bottom of the flower, its invariable 
aim. And perhaps in unison with this, is the frequently 
cucullate nature of the labellum. 
The situation of the stigma, and its form, being in fact no- 
thing but a pit in the face of the column, lined with viscid 
tissue, may be argued as in part assisting to this end. 
However unphilosophical the supposition of the necessity of 
the agency of insects may be, in as much as it appears to argue 
imperfection in the plant, and that too of a high degree, yet it 
is not so unphilosophical in its assumptions as the first theory. 
Besides it has analogy of the strongest nature in its favour, 
and viewed even in its imperfection, itis a beautiful instance of 
the mutual dependencies evinced in the works of natnre. 
But the idea of imperfection disappears when we keep in view 
the simple resources by which nature overcomes her difficul- 
ties. The plants of this family present very generally the 
most beautiful flowers, striking in their colours, and often 
even assuming the peculiar shapes and forms of insects, as if 
the better to attract them etc. On this point I quote from 
Dr. Lindley who has paid great attention to the family. 
‘‘Orchidace are remarkable for the bigarrhe figure of their 
multiform flower, which sometimes represents an insect" 
etc. p. 337. Nor is the motion of certain of their flowers on 
the application of a stimulus to be omitted, as calculated to 
promote the kind of agency adverted to. 
Lastly, the inflorescence is almost always of a form, by 
which contact with one flower, leads almost certainly to con- 
tact with others. 
On the other hand the Bauerian theory involves many 
circumstances of a contradictory nature. 
In the first place it errs against general analogy in suppos- 
ing that impregnation takes place generally before the open- 
ing of the flower. In the second place it takes no account 
